config: increase default trickle delay from 30s to 1m30s

In this commit, we increase the default trickle delay from 30s to 1m30s.
We do this as before we implement the new INV gossip mechanism, we want
to de-emphasise the quick propagation of updates through the network
which eats up bandwidth.

config.go

@@ -49,7 +49,7 @@ const (
 	defaultRPCHost             = "localhost"
 	defaultMaxPendingChannels  = 1
 	defaultNoSeedBackup        = false
-	defaultTrickleDelay        = 30 * 1000
+	defaultTrickleDelay        = 90 * 1000
 	defaultInactiveChanTimeout = 20 * time.Minute
 	defaultMaxLogFiles         = 3
 	defaultMaxLogFileSize      = 10