CI tests: use old schema when testing hostmask-based sudo rules
    
    Newer versions of sssd use native IPA schema to process sudo rules.
    However, this schema currently has no support for hostmask-based rules
    and causes some sudo CI tests to fail. We have to temporarily set
    sssd.conf to use ou=sudoers,$SUFFIX as a sudo rule search base when
    executing them.
    
    https://fedorahosted.org/freeipa/ticket/5625
    
    Reviewed-By: Tomas Babej <tbabej@redhat.com>