Reverse proxy instructions should highlight base.setup.env change for NETBIRD_SIGNAL_PROTOCOL="https"

[Aterfax]

docs/src/pages/selfhosted/selfhosted-guide.mdx

Lines 159 to 173 in 5ef2a51

	### Configuration for NetBird
	In `setup.env`:
	- Set ```NETBIRD_DOMAIN``` to your domain, e.g. `demo.netbird.io`
	- Set ```NETBIRD_DISABLE_LETSENCRYPT=true```
	- Add ```NETBIRD_MGMT_API_PORT``` to your reverse-proxy TLS-port (default: 443)
	- Add ```NETBIRD_SIGNAL_PORT``` to your reverse-proxy TLS-port
	Optional:
	- Add ```TURN_MIN_PORT``` and ```TURN_MAX_PORT``` to configure the port-range used by the Turn-server
	<Note>
	The `coturn`-service still needs to be directly accessible under your set-domain as it uses UDP for communication.
	</Note>

Recently started using NetBird with traefik to do the reverse proxy and found that connectivity to the "signal" endpoint was not working when using SSL unless the protocol in base.setup.env was changed as NETBIRD_SIGNAL_PROTOCOL="https".

I think this being highlighted would be a useful addition to this section, but I defer to folks with more experience to know if this is correct.