Update documentation for https websocket function in PA server config

[Airforc]

In order to use https with nginx, cors_allowed_origins in /server/server_config.cfg needs to have the https://subdomain.domain.com specified that is directed to PA.

[Webserver]
# Allowed CORS origins # If not specified, only the host runnig the server is allowed
# Allowed values are: ['*'], ['some-address.xyz', 'other-address.xyz'], [] # More information on the meaning of these values can be found at
# https://python-socketio.readthedocs.io/en/latest/api.html#asyncserver-class **cors_allowed_origins = https://subdomain.domain.com**