lib-storage: Added asserts to make sure mailbox_open() is called early enough.
lib-storage: Added asserts to make sure mailbox_open() is called early enough.

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