Fix my js_loader patch

* still call the callback when skipping duplicate file.  This updates the completed flags, and so the overall "we're done" callback fires properly.

common/lib/xmodule/xmodule/js/src/javascript_loader.coffee

@@ -62,5 +62,9 @@ class @JavascriptLoader
         # Need to use the DOM elements directly or the scripts won't execute
         # properly.
         $('head')[0].appendChild(s)
-        $(placeholder).remove()
+      else
+        # just call the completion callback directly, without reloading the file
+        completionHandlerGenerator(index)()
+      $(placeholder).remove()
+