on eos signal from sink between src and webrtcbin, disconnect from whip

[danjenkins]

EDIT Removed the error listening hacky code.

Now you pass in an extra param to give it a name of a sink between the source that may end by itself and webrtcbin Typically you're going to have a demuxer or a parser or a decoder anyway so just add a name to that "sink" and pass that name in as a param under -e

[danjenkins]

@lminiero fixed the merge conflict

[lminiero]

Thanks for the quick fixes, merging!