lib-storage: Fixed mail_storage_copy_can_use_hardlink() for mode=0600 with different uids.
lib-storage: Fixed mail_storage_copy_can_use_hardlink() for mode=0600 with different uids.

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