BUG: src automatically added to video tag

Hi @artf,

Thanks for building and maintaining this wonderful package.

Issue I am using Nicepages to build template and upload it to my webapp. I have integrated with Grapesjs, which allows admins to edit the templates easily. The issue that I am facing is Nicepages adds video tag as follows

<video>
    <source src="PATH_TO_VIDEO" type="mime/type"/>
</video>

When this template is opened in the Grapesjs, grapesjs adds source to the parent video tag like this

<video src="SOME_SVG_CODE" >
    <source src="PATH_TO_VIDEO" type="mime/type"/>
</video>

If you can help me to resolve this issue, that would be great. I am happy to fix it in GrapesJS and make a pull request