Describe the bug

It's impossible to store a nickserv password or certificate on OFTC.

OFTC doesn't support using server password to identify to services, which means currently there's no way to automatically reidentify after connection blips between the oftc bridge and their network. OFTC does support cert auth.

To Reproduce
Steps to reproduce the behavior:

1. Connect to OFTC. Register your nickname with NickServ.
2. Tell @oftc-irc:​matrix.org to !storepass foo
3. !reconnect

Expected behaviour

Nickname gets authenticated on NickServ (through certfp) on reconnection.

Actual behaviour

Nickname doesn't get authenticated, making it impossible to rejoin some channels. No error messages.

Additional context
Add any other context about the problem here.

There was #459 which got closed even though the problem still exists.

#1128 to add certfp was abandoned. #1331 which was done instead doesn't fix the issue - authentication fails even with !username.

#747 tracks certfp support, but doesn't make clear that authentication is currently completely broken on OFTC.