- gives ListenerCtrlChannel Min: 0 constraints per underlay type plus
MinTotalUnderlays: 1 in its configs, so the controller accepts the
high/low-priority grouped underlays the router dials while still closing the
channel only when its last underlay is lost
- restores the multi-underlay behavior the v4 listener-side SetMinTotal(1)
provided, which the channel/v5 migration dropped
- works around channel/v5 not yet treating MinTotalUnderlays alone as a
multi-underlay signal
Paul Lorenz
2dc4075446