Comment 0 for bug 1547964

If video clip is blanked with escape item and escape item is triggered again the next traceback appears:

Traceback (most recent call last):
  File "E:\bzr\openlp\refix-win-display\openlp\core\ui\slidecontroller.py", line 516, in live_escape
    self.media_controller.media_stop(self)
  File "E:\bzr\openlp\refix-win-display\openlp\core\ui\media\mediacontroller.py", line 661, in media_stop
    self.current_media_players[controller.controller_type].stop(display)
  File "E:\bzr\openlp\refix-win-display\openlp\core\ui\media\systemplayer.py", line 181, in stop
    display.media_player.durationChanged.disconnect()
TypeError: disconnect() failed between 'durationChanged' and all its connections

Win 8.1 / 2.4 / System / VLC / Webkit enabled.