removed a String with a Constant (JavaCore.NATURE_ID)

plugins/org.yakindu.sct.generator.genmodel.ui/META-INF/MANIFEST.MF

@@ -29,8 +29,9 @@ Require-Bundle: org.yakindu.sct.generator.genmodel;visibility:=reexport,
  org.eclipse.emf.mwe2.language.ui;bundle-version="2.0.1",
  de.itemis.xtext.utils.jface;bundle-version="1.0.0",
  org.eclipse.xtext.xbase.lib;bundle-version="2.3.0"
-Import-Package: org.apache.log4j,
- org.apache.commons.logging
+Import-Package: org.apache.commons.logging,
+ org.apache.log4j,
+ org.eclipse.jdt.core
 Bundle-RequiredExecutionEnvironment: J2SE-1.5
 Export-Package: org.yakindu.sct.generator.genmodel.ui,
  org.yakindu.sct.generator.genmodel.ui.contentassist.antlr,