lib-auth: Less leaky fix to previous auth_master_*() bugfix.
lib-auth: Less leaky fix to previous auth_master_*() bugfix.

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