If trying to log in with password having illegal characters, make sure we fail early.
If trying to log in with password having illegal characters, make sure we
fail early.

--HG--
branch : HEAD

jkerihuel/dovecot,jkerihuel/dovecot,jwm/dovecot-notmuch,jwm/dovecot-notmuch,jwm/dovecot-notmuch,jwm/dovecot-notmuch,jwm/dovecot-notmuch,jkerihuel/dovecot,jkerihuel/dovecot,jkerihuel/dovecot