topology: fix swapped topologysegment-reinitialize behavior
setting "nsds5BeginReplicaRefresh;left" to "start" reinintializes the
right node and not the left node. This patch fixes API to match the
behavior.
part of: https://fedorahosted.org/freeipa/ticket/4302
Reviewed-By: Martin Babinsky <mbabinsk@redhat.com>