mbox: Support deleting a directory if it contains an empty .imap/ directory.
mbox: Support deleting a directory if it contains an empty .imap/ directory.

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