gossip: Fix hasOutgoingLocked to consider pending connections
gossip: Fix hasOutgoingLocked to consider pending connections

This eliminates another source of duplicate connections from one node to
another (because if a client gets a forwardingAddr for a node that it's
already in the process of connecting to, it'll now recognize it's
already in the process of connecting to it).

paperstreet/cockroach,paperstreet/cockroach,paperstreet/cockroach,paperstreet/cockroach,paperstreet/cockroach,paperstreet/cockroach,paperstreet/cockroach,paperstreet/cockroach