Instead of updating the configuration, we configure a new Server instance and
then migrate Listeners that still exist to it. Open client connections are
left completely untouched.
Closes https://todo.sr.ht/~emersion/tlstunnel/1
Always listen on all hosts. Only use the host part of a frontend
address for TLS cert names.
Customizing the listen host will be better done with a `bind`
directive, like Caddy does.
minus
Simon Ser