IKEv1 quick exchange where the responder's haf quick exchange is unrouted

The responder completes the first part of the quick mode exchange, only
to then be unrouted.

  routing: stop ESTABLISH_INBOUND, UNROUTED_BARE_NEGOTIATION->UNROUTED_INBOUND, PERMANENT; ok=yes; negotiating_ike_sa #1 established_ike_sa #1 newest_routing_sa #0->#2

this can happen when the initiator disappears part way through the
exchange


