Does not like video devices remounted via Docker's -v option about ros-webrtc

[aisch]

@haidai libjingle actually uses v4l2 card type and not the device. we hacked it to support devices so we can amend that to e.g. first resolve if symlink.

[aisch]

@haidai do u still need this? going to close if not

[aisch]

reopen if still needed

[haidai]

We're not using docker anymore but that might change depending on what Ben decides.