gossipd: don't try to connect to non-routable addresses.

Someone could try to announce an internal address, and we might probe
it.

This breaks tests, so we add '--dev-allow-localhost' for our tests, so
we don't eliminate that one.  Of course, now we need to skip some more
tests in non-developer mode.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

gossipd/routing.h

@@ -162,6 +162,9 @@ struct routing_state {
 	 * restarts */
 	struct gossip_store *store;
 
+	/* For testing, we announce and accept localhost */
+	bool dev_allow_localhost;
+
         /* A map of channels indexed by short_channel_ids */
 	UINTMAP(struct chan *) chanmap;
 };
@@ -183,7 +186,8 @@ struct route_hop {
 struct routing_state *new_routing_state(const tal_t *ctx,
 					const struct bitcoin_blkid *chain_hash,
 					const struct pubkey *local_id,
-					u32 prune_timeout);
+					u32 prune_timeout,
+					bool dev_allow_localhost);
 
 struct chan *new_chan(struct routing_state *rstate,
 		      const struct short_channel_id *scid,