ipatests: fix teardown method
    
    The teardown method of the integration tests is calling
      tasks.uninstall_master(replica)
    which in turn does ipa server-del + ipa-server-install --uninstall
    
    The uninstallation is called by default with --ignore-last-of-role
    and --ignore-topology-disconnect excepted if the domain-level is 0,
    in which case these options are not supported by uninstall.
    
    The issue is that the call to get domain level fails because the
    server has already been removed, and the code handles that failure by
    assuming domain level =0, resulting in missing --ignore-last-of-role.
    
    To workaround the issue, the call to tasks.uninstall should be done
    with the actual domain level:
      tasks.uninstall_master(replica, domain_level=...)
    
    Fixes: https://pagure.io/freeipa/issue/8280
    Reviewed-By: Sergey Orlov <sorlov@redhat.com>
    Reviewed-By: Kaleemullah Siddiqui <ksiddiqu@redhat.com>