Videoconference TCP fallback not working

We need to check if 4443 is served through firewall and proxy, as 443 is occupied by web server.

JVB 2017-12-07 08:01:49.851 WARNING: [1381668] org.jitsi.videobridge.EndpointMessageTransport.log() SCTP connection with d7cb13ab not ready yet.
JVB 2017-12-07 08:01:49.851 WARNING: [1381668] org.jitsi.videobridge.EndpointMessageTransport.log() No available transport channel, can't send a message

Issue: https://github.com/jitsi/jitsi-meet/issues/1900

Docs: https://github.com/jitsi/jitsi-videobridge/blob/master/doc/tcp.md