auth: Keep master connection referenced during USER lookups. Fixes a crash when master disconnected before USER lookup was finished.
auth: Keep master connection referenced during USER lookups.
Fixes a crash when master disconnected before USER lookup was finished.

LTD-Beget/dovecot,LTD-Beget/dovecot,LTD-Beget/dovecot,LTD-Beget/dovecot,LTD-Beget/dovecot