Remove obsolete tests from test_caless.py
    
    Related issue #4270 is closed as "won't fix" after 4 years.
    The tests are obsolete now.
    
    See: https://pagure.io/freeipa/issue/4271
    See: https://pagure.io/freeipa/issue/4270
    
    Signed-off-by: Sergey Orlov <sorlov@redhat.com>
    Reviewed-By: Florence Blanc-Renaud <frenaud@redhat.com>
    Reviewed-By: Florence Blanc-Renaud <flo@redhat.com>