SYSDB: override_gid not working for subdomains
The override_gid is not propagated to subdomain. This patch
assigns subdomain's override_gid to the value comming from
parent domain.
Resolves:
https://pagure.io/SSSD/sssd/issue/4061
Reviewed-by: Pavel Březina <pbrezina@redhat.com>
(cherry picked from commit 626c9c2f41e347c3df6f530fcdf7db96741c385f)