07a471d ipatests: in test_trust.py fix parent class

Authored and Committed by sorlov 5 years ago
    ipatests: in test_trust.py fix parent class
    
    TestExternalTrustWithRootDomain was inherited from ADTrustSubdomainBase
    This caused that external trust was checked two times with subdomain
    and was not checked with root domain.
    
    Related to https://pagure.io/freeipa/issue/7889
    
    Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
    Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>