add reverse proxy support for SSH and VNC websocket + nginx config

[aderumier]

Currently the vnc && ssh websockets ports send to the wss client are hardcoded to 5001 && 5002.

This patch assume that if client use port 80/443, it's using a production reverse proxy, and reuse this port the websocket connections

[mkellermann97]

Hi @aderumier,
We've looked into this. The issue is that most of our users don't use port 5000 – they're running on 443 + 2 or similar. Merging this could potentially break a lot of setups.
If you could include a fix for that in your implementation, we'd really appreciate it.

Regards,
Marcus

[aderumier]

hi, no problem, I'll look to add an option to enable reverse proxy, and find a way to return the correct port dynamically to the client.