[GStreamer] Media tests fix after r141695.

Rubber-stamped by Martin Robinson.

* platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.cpp:
(WebCore::MediaPlayerPrivateGStreamer::setPlaybinURL): Remove
both fragment and query string for file:// uris before loading.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@141697 268f45cc-cd09-0410-ab3c-d52691b4dbfc