Do not crash client basedn discovery when SSF not met
    
    ipa-client-install runs anonymous search in non-rootdse space which
    may raise UNWILLING_TO_PERFORM error. This case was only covered for
    BIND, but not for the actual LDAP queries.
    
    https://fedorahosted.org/freeipa/ticket/4459
    
    Reviewed-By: Petr Viktorin <pviktori@redhat.com>