NPE in crawl setting when registered the permissions field as blank.

[3rdarm]

java.lang.NullPointerException
    at org.codelibs.fess.app.web.admin.webconfig.AdminWebconfigAction.lambda$getWebConfig$3593(AdminWebconfigAction.java:300)
    at org.dbflute.optional.BaseOptional.callbackMapping(BaseOptional.java:228)
    at org.dbflute.optional.OptionalEntity.map(OptionalEntity.java:287)
    at org.codelibs.fess.app.web.admin.webconfig.AdminWebconfigAction.getWebConfig(AdminWebconfigAction.java:293)
    at org.codelibs.fess.app.web.admin.webconfig.AdminWebconfigAction.update(AdminWebconfigAction.java:229)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.lastaflute.web.ruts.GodHandableAction.invokeExecuteMethod(GodHandableAction.java:345)
    at org.lastaflute.web.ruts.GodHandableAction.actuallyExecute(GodHandableAction.java:316)
    at org.lastaflute.web.ruts.GodHandableAction.doExecute(GodHandableAction.java:156)
    at org.lastaflute.web.ruts.GodHandableAction.lambda$transactionalExecute$148(GodHandableAction.java:147)
    at org.lastaflute.db.jta.stage.JTATransactionStage.doPerform(JTATransactionStage.java:66)
    at org.lastaflute.db.jta.stage.JTATransactionStage.lambda$requiresNew$92(JTATransactionStage.java:55)
    at org.lastaflute.di.tx.adapter.JTATransactionManagerAdapter.requiresNew(JTATransactionManagerAdapter.java:60)
    at org.lastaflute.db.jta.stage.JTATransactionStage.requiresNew(JTATransactionStage.java:54)
    at org.lastaflute.db.jta.stage.JTATransactionStage.selectable(JTATransactionStage.java:93)
    at org.lastaflute.web.ruts.GodHandableAction.transactionalExecute(GodHandableAction.java:146)
    at org.lastaflute.web.ruts.GodHandableAction.godHandyExecute(GodHandableAction.java:127)
    at org.lastaflute.web.ruts.GodHandableAction.execute(GodHandableAction.java:111)
    at org.lastaflute.web.ruts.ActionRequestProcessor.performAction(ActionRequestProcessor.java:194)
    at org.lastaflute.web.ruts.ActionRequestProcessor.fire(ActionRequestProcessor.java:130)
    at org.lastaflute.web.ruts.ActionRequestProcessor.process(ActionRequestProcessor.java:101)
    at org.lastaflute.web.servlet.filter.RequestRoutingFilter.processAction(RequestRoutingFilter.java:239)
    at org.lastaflute.web.servlet.filter.RequestRoutingFilter.routingToAction(RequestRoutingFilter.java:191)
    at org.lastaflute.web.servlet.filter.RequestRoutingFilter.lambda$createActionPathHandler$265(RequestRoutingFilter.java:164)
    at org.lastaflute.web.path.ActionPathResolver.actuallyHandleActionPath(ActionPathResolver.java:269)
    at org.lastaflute.web.path.ActionPathResolver.doHandleActionPath(ActionPathResolver.java:191)
    at org.lastaflute.web.path.ActionPathResolver.handleActionPath(ActionPathResolver.java:111)
    at org.lastaflute.web.servlet.filter.RequestRoutingFilter.doFilter(RequestRoutingFilter.java:104)
    at org.lastaflute.web.servlet.filter.LastaToActionFilter.viaEmbeddedFilter(LastaToActionFilter.java:152)
    at org.lastaflute.web.servlet.filter.LastaToActionFilter.viaInsideHookDeque(LastaToActionFilter.java:143)
    at org.lastaflute.web.servlet.filter.LastaToActionFilter.viaInsideHook(LastaToActionFilter.java:127)
    at org.lastaflute.web.servlet.filter.LastaToActionFilter.doFilter(LastaToActionFilter.java:119)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
    at org.lastaflute.web.servlet.filter.LastaShowbaseFilter.toNextChain(LastaShowbaseFilter.java:162)
    at org.lastaflute.web.servlet.filter.LastaShowbaseFilter.lambda$viaEmbeddedFilter$272(LastaShowbaseFilter.java:141)
    at org.lastaflute.web.servlet.filter.RequestLoggingFilter.actuallyFilter(RequestLoggingFilter.java:212)
    at org.lastaflute.web.servlet.filter.RequestLoggingFilter.doFilter(RequestLoggingFilter.java:197)
    at org.lastaflute.web.servlet.filter.LastaShowbaseFilter.viaEmbeddedFilter(LastaShowbaseFilter.java:139)
    at org.lastaflute.web.servlet.filter.LastaShowbaseFilter.viaOutsideHookDeque(LastaShowbaseFilter.java:130)
    at org.lastaflute.web.servlet.filter.LastaShowbaseFilter.viaOutsideHook(LastaShowbaseFilter.java:114)
    at org.lastaflute.web.servlet.filter.LastaShowbaseFilter.doFilter(LastaShowbaseFilter.java:106)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
    at org.codelibs.fess.filter.WebApiFilter.doFilter(WebApiFilter.java:51)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
    at org.lastaflute.web.servlet.filter.LastaPrepareFilter.toNextFilter(LastaPrepareFilter.java:279)
    at org.lastaflute.web.servlet.filter.LastaPrepareFilter.viaHotdeploy(LastaPrepareFilter.java:242)
    at org.lastaflute.web.servlet.filter.LastaPrepareFilter.viaLastaDiContext(LastaPrepareFilter.java:229)
    at org.lastaflute.web.servlet.filter.LastaPrepareFilter.doFilter(LastaPrepareFilter.java:202)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
    at org.codelibs.fess.filter.EncodingFilter.doFilter(EncodingFilter.java:119)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:108)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:522)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:1110)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:785)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1425)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:745)