Bug 323048 "Copy Folder Location" does not work anymore

p=Frank Wein <bugzilla@mcsmurf.de> r=me sr=bienvenu

mailnews/base/resources/content/mailContextMenus.js

@@ -599,7 +599,10 @@ function CopyFolderUrl()
   {
     var folderResource = GetSelectedFolderResource();
     if (folderResource)
+    {
+      var msgFolder = folderResource.QueryInterface(Components.interfaces.nsIMsgFolder);
       CopyString(msgFolder.folderURL);
+    }
   }
   catch (ex) 
   {