ipatests: fix test_replica_uninstall_deletes_ruvs
    
    test_topology.py is failing because of a wrong scenario.
    Currently, test_replica_uninstall_deletes_ruvs does:
    - install master + replica with CA
    - ipa-replica-manage list-ruv to check that the repl is
    propery setup
    - ipa-replica-manage del $replica
    - (on replica) ipa-server-install --uninstall -U
    - ipa-replica-manage list-ruv to check that replica
    does not appear any more in the RUV list
    
    When ipa-replica-manage del is run, the topology plugin
    creates 2 tasks cleanallruvs (one for the domain, one for the ca)
    and they are run asynchronously. This means that the ruvs may
    still be present when the test moves forward and calls list-ruv.
    
    The test should wait for the cleanallruvs tasks to finish before
    checking that list-ruv does not display replica anymore.
    
    Fixes https://pagure.io/freeipa/issue/7545
    
    Reviewed-By: Thierry Bordaz <tbordaz@redhat.com>
    Reviewed-By: Rob Crittenden <rcritten@redhat.com>