ipatests: use krb5_trace in TestIpaAdTrustInstall
    
    tasks.create_active_user can fail in a subtle way when there
    are two IPA servers due to replication delays.
    Using the debug-enabled version of create_active_user helps
    determine whether there is another underlying issue and, in
    general, prevents the above problem.
    
    Fixes: https://pagure.io/freeipa/issue/8944
    Signed-off-by: François Cami <fcami@redhat.com>
    Reviewed-By: Anuja More <amore@redhat.com>