Opportunistically use relay that a node was last seen on #141
Description
Description
Sometimes, when a remote node contacts the local node, its doing through the local node's home relay.
However, when we're still connecting to the remote node's home relay, we may want to send traffic opportunistically through the last relay we have seen that node send traffic to.
This would make latency much better after we have received a packet from that node, since it's most likely still connected with the corresponding relay.