When using `auth_remove`, the key indices for the default helper, mod and admin passwords were not properly adjusted, causing the wrong passwords to be used for the username-less logins.
The key indices for connected clients were also not properly adjusted, causing the wrong identity to be shown for currently authenticated clients when using the `status` command.
Closes#6427.
Purely automatic change. In case of conflict with this change, apply the
other change and rerun the formatting to restore it:
$ python scripts/fix_style.py
This uses an extended protocol message to signal that rcon
authentication might require a username, allowing the client to enable
the username prompt.
Add a forgotten logout on key update