Don't only build libSEDML (opencor#2053).

CMakeLists.txt

@@ -33,7 +33,6 @@ option(USE_PREBUILT_QSCINTILLA_PACKAGE "Use the pre-built version of the QScinti
 option(USE_PREBUILT_QWT_PACKAGE "Use the pre-built version of the Qwt package" ON)
 option(USE_PREBUILT_SUNDIALS_PACKAGE "Use the pre-built version of the SUNDIALS package" ON)
 option(USE_PREBUILT_ZLIB_PACKAGE "Use the pre-built version of the zlib package" ON)
-set(USE_PREBUILT_LIBSEDML_PACKAGE OFF)
 
 if(ENABLE_TEST_PLUGINS)
     option(USE_PREBUILT_ZINC_PACKAGE "Use the pre-built version of the Zinc package" ON)
@@ -930,11 +929,6 @@ set(PLUGINS
     widget/MathMLViewerWidget
     widget/WebViewerWidget
 )
-set(PLUGINS
-    thirdParty/libSBML
-    thirdParty/libNuML
-    thirdParty/libSEDML
-)
 
 if(ENABLE_TEST_PLUGINS)
     list(APPEND PLUGINS