The variable maxNumClients was unused, while connectionsPerClient was
used for spawning multiple proxyPairs. The former is a more appropriate
name for the multiplexing behaviour we use it for.
Multiplexing now just works thanks to implementing ticket #31310.
Some files were omitted in the .eslintignore, left as an exercise to the
reader.
We probably want to reduce amount of globals overall and use proper es
modules.
No idea why but, with it, when a client disconnects the datachannel
doesn't close. This wasn't an issue prior to 359600d since the
configuration wasn't being passed to the peerconnection constructor.
This probably just makes the url invalid and falls back to a default in
libwebrtc.
