Merge pull request #739 from Yakindu/issue_738

#738: Fixed NPE.

plugins/org.yakindu.sct.generator.java/src/org/yakindu/sct/generator/java/features/EventBasedRunnableFeature.xtend

@@ -37,7 +37,8 @@ class EventBasedRunnableFeature {
 	}
 
 	def getNameSuffix(GeneratorEntry it) {
-		if (featureEventRunnable != null)
+		if (featureEventRunnable != null &&
+			featureEventRunnable.getParameterValue(IJavaFeatureConstants::VALUE_NAME_SUFFIX) != null)
 			featureEventRunnable.getParameterValue(IJavaFeatureConstants::VALUE_NAME_SUFFIX).stringValue
 		else
 			IJavaFeatureConstants::RUNNABLE_WRAPPER_NAME_SUFFIX_DEFAULT