doveadm who: Don't crash if server happens to send broken input. Found by Coverity.
doveadm who: Don't crash if server happens to send broken input.
Found by Coverity.

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