Fix HTTPS handling constructing baseUrl

Construct baseUrl in protocol relative manner. e.g. 'https:'/'http:' +
'//player.vimeo.com/video'

http://vimeo.com/forums/feature_requests/topic:38866

http://vimeo.com/help/faq/sharing-videos/embedding-videos#can-i-embed-my-video-on-an-https-domain