Fixed regex for Colbert Report playlist clips

Previously the regex would match for playlists but not for individual clips accessed as part of the playlist.
Previously working:
http://thecolbertreport.cc.com/video-playlists/xi35i8/colbert-report-04091
Previously not working:
http://thecolbertreport.cc.com/video-playlists/xi35i8/colbert-report-04091/2uxo91