lib-storage: mailbox_get_metadata() now opens the mailbox only if it's necessary.
lib-storage: mailbox_get_metadata() now opens the mailbox only if it's necessary.

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