ipatests: remove fixture call and wait to get things settle
    
    system date moved in order to expire the certs. Sometime it
    is observed that subsequent operation fails with 500 error for CA,
    hence restart the services after moving date and wait for sometime
    to get things settle.
    
    Also the tests was calling fixture which is not required for it, hence
    removed it as well.
    
    Fixes: https://pagure.io/freeipa/issue/9348
    
    Signed-off-by: Mohammad Rizwan <myusuf@redhat.com>
    Reviewed-By: Florence Blanc-Renaud <flo@redhat.com>