Allow '-' and '_'  for  youtube video_id
Allow '-' and '_'  for  youtube video_id

Signed-off-by: Alex Rodrigues <60c6d277a8bd81de7fdde19201bf9c58a3df08f4@openhost.es>
vgrish/panorama-php,frandieguez/panorama-php,tsukasa-mixer/panorama-php,frandieguez/panorama-php,vgrish/panorama-php,tsukasa-mixer/panorama-php