only enable migrate cvs root action on directories under CVS

plugins/cvs/cvs-plugin/src/com/intellij/cvsSupport2/actions/MigrateCvsRootAction.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2011 JetBrains s.r.o.
+ * Copyright 2000-2011 JetBrains s.r.o.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -45,6 +45,7 @@ public class MigrateCvsRootAction extends AnAction {
   public MigrateCvsRootAction() {
     super();
     myVisibility.shouldNotBePerformedOnFile();
+    myVisibility.addCondition(ActionOnSelectedElement.FILES_ARE_UNDER_CVS);
   }
 
   @Override