fix(auth): using the wrong fallback auth-server

[Khaomi]

Auth mode don't output list of auth urls anymore.

So instead of falling back to one singular auth url, we guess based on which hub the server listing is from, if it is from the old hub, then it probably use old auth, if it use the new hub, then it probably use new auth, if it use simplestation hub, then it probably use simplestation's auth.

Sample from Goobstation

[DEATHB4DEFEAT]

I'd rather try to get upstreams to add auth provider to their API than do this, I'll leave this open in case they deny that change.

[Khaomi]

Sounds good!

[rumaks-xyz]

What about adding an option to override the auth server for favorites? @DEATHB4DEFEAT

[Skyedra]

It may take a long while for both upstreams to get auth_methods added and for forks to update to using it, assuming the upstreams are willing to at all. (auth_methods requires an RT engine update, and many forks are on many different RT versions that may not update soon. Thus getting all the servers to update to a required RT version is going to take a long while.)

So a workaround right now, while people are looking for multi-auth launchers to try, seems like a good idea.