DogtagInstance.backup_config uses shutil.copy to create a backup of the
config file. The function does not retain owner and group, so it creates a
backup as user and group root:root.
Closes: https://pagure.io/freeipa/issue/7426
Signed-off-by: Christian Heimes <cheimes@redhat.com>
Reviewed-By: Alexey Slaykovsky <alexey@slaykovsky.com>