Center align in CKEditor not work for "Embed Media".

1. Insert youtube code, used button "Embed Media" in CKEditor. Code:

<p>
	<div class="media_embed" height="360px" width="480px">
		<iframe allowfullscreen="" frameborder="0" height="360px" src="http://www.youtube.com/embed/n1bxT..." width="480px"></iframe></div>
</p>

2. Select embed object in editor and click button "Center". Code after this:

<p class="rtecenter">
	<div class="media_embed" height="360px" width="480px">
		<iframe allowfullscreen="" frameborder="0" height="360px" src="http://www.youtube.com/embed/n1bxT..." width="480px"></iframe></div>
</p>

3. Save node.

4. Code embed after save:

<p class="rtecenter">&nbsp;</p>
<div class="media_embed" height="360px" width="480px">
	<iframe allowfullscreen="" frameborder="0" height="360px" src="http://www.youtube.com/embed/n1bxT..." width="480px"></iframe></div>
<p>&nbsp;</p>