fix for embedded videos (iframe type)

Fix for iframe type embedded video:
<iframe width="560" height="315" src="//www.youtube.com/embed/-z4Cpmlzv1Y" frameborder="0" allowfullscreen></iframe>
<iframe src="//player.vimeo.com/video/72625639" width="500" height="281" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>