upgrade: add missing suffix to http instance
During an upgrade, http.suffix is used to identify ldap entry when
configuring kdc proxy. When the suffix is missing, the script crashed
when enabling KDC proxy, because it used invalid DN.
Fixes https://pagure.io/freeipa/issue/6920
Reviewed-By: Martin Basti <mbasti@redhat.com>
Reviewed-By: Martin Babinsky <mbabinsk@redhat.com>