IDEA-138381 Restart for Plugin Updates is prompted even though no changes were introduced

platform/platform-impl/src/com/intellij/openapi/options/newEditor/ConfigurableEditor.java

@@ -125,7 +125,8 @@ class ConfigurableEditor extends AbstractEditor implements AnActionListener, AWT
 
   @Override
   boolean apply() {
-    return setError(apply(myConfigurable));
+    // do not apply changes of a single configurable if it is not modified
+    return setError(apply(myApplyAction.isEnabled() ? myConfigurable : null));
   }
 
   void openLink(Configurable configurable) {