Update movie.actions.js to allow playing trailers when using https

When the server is hosted using https, an error occurs when trying to play trailers:

[blocked] The page at https://example.com:5000/manage/ ran insecure content from http://gdata.youtube.com/feeds/videos?...

By removing the http: from the data_url var a protocol-relative link is used instead. This will throw an https warning, but the trailer will successfully play.