Use api.env.container_sysaccounts
Refactor code to use api.env.container_sysaccounts instead of
('cn', 'sysaccounts'), ('cn', 'etc')
Related: https://pagure.io/freeipa/issue/8276
Signed-off-by: Christian Heimes <cheimes@redhat.com>
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>