Removing external=true from theme function increases reliability of embed code

We had some problems with the embed code not working. We're using the module to embed videos hosted locally and adding "external=true" along with "absolute = true" ended up creating relative urls (I'm not sure why the url() function does that, but it does...).

This caused problems with the embed code depending on themes.

I removed the "external=true" and everything is working better.

It's also a bit aggressive to assume external=true when these are actually internal urls.