youtube: replace deprecated gdata_youtube_video_look_up_content
youtube: replace deprecated gdata_youtube_video_look_up_content

It always return NULL as this is no longer supported by Google.

grl-youtube.c: In function ‘build_media_from_entry’:
grl-youtube.c:571:2: warning: ‘gdata_youtube_video_look_up_content’ is
deprecated: Use gdata_youtube_video_get_player_uri instead
[-Wdeprecated-declarations]
  gdata_youtube_video_look_up_content (video,
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

https://bugzilla.gnome.org/show_bug.cgi?id=770806

jasuarez/grilo-plugins,jasuarez/grilo-plugins,MikePetullo/grilo-plugins,grilofw/grilo-plugins,MikePetullo/grilo-plugins,grilofw/grilo-plugins,GNOME/grilo-plugins,GNOME/grilo-plugins,MikePetullo/grilo-plugins