Don't assert-crash with 0-byte sized "mboxes".
Don't assert-crash with 0-byte sized "mboxes".

damoxc/dovecot,LTD-Beget/dovecot,damoxc/dovecot,Distrotech/dovecot,Distrotech/dovecot,damoxc/dovecot,LTD-Beget/dovecot,LTD-Beget/dovecot,Distrotech/dovecot,Distrotech/dovecot,LTD-Beget/dovecot,Distrotech/dovecot,damoxc/dovecot,LTD-Beget/dovecot,damoxc/dovecot