adapt to testing under confined users too
    
    The root user on a system is usually not confined by SELinux (context:
    unconfined_u:unconfined_r:unconfined_t), but there are security
    standarts which require the root user to be confined by SELinux
    (context: sysadm_u:sysadm_r:sysadm_t).
    In order to use this automated test on such systems, certain code
    changes were necessary.