Remove NPE from ContainerNotAvailableException on debug level loggging

[marevol]

2016-06-09 15:08:06,758 [IndexUpdater] ERROR IndexUpdater is terminated.
org.codelibs.fess.exception.ContainerNotAvailableException: java.lang.NullPointerException
    at org.codelibs.fess.util.ComponentUtil.getComponent(ComponentUtil.java:356)
    at org.codelibs.fess.util.ComponentUtil.getIntervalControlHelper(ComponentUtil.java:239)
    at org.codelibs.fess.indexer.IndexUpdater.getAccessResultList(IndexUpdater.java:517)
    at org.codelibs.fess.indexer.IndexUpdater.run(IndexUpdater.java:213)
Caused by: java.lang.NullPointerException: null
    at org.lastaflute.di.core.meta.impl.ComponentDefImpl.getComponentDeployer(ComponentDefImpl.java:236)
    at org.lastaflute.di.core.meta.impl.ComponentDefImpl.getComponent(ComponentDefImpl.java:91)
    at org.lastaflute.di.core.meta.impl.LaContainerImpl.getComponent(LaContainerImpl.java:102)
    at org.lastaflute.di.core.SingletonLaContainer.getComponent(SingletonLaContainer.java:52)
    at org.codelibs.fess.util.ComponentUtil.getComponent(ComponentUtil.java:354)
    ... 3 common frames omitted