fundingManager: use NotifyWhenOnline when sending fundingLocked.

The fundingManager will register with the server to get notified
when the targetted peer comes online, in case of a failed send
of the fundingLocked message. This is necessary because if the
peer is not connected yet (or was disconnected while we were
waiting for the funding tx to confirm), we cannot continue the
the opening process before the peer successfully has received
the fundingLocked.

lnd.go

@@ -186,10 +186,11 @@ func lndMain() error {
 				idPrivKey.PubKey())
 			return <-errChan
 		},
-		ArbiterChan:    server.breachArbiter.newContracts,
-		SendToPeer:     server.SendToPeer,
-		FindPeer:       server.FindPeer,
-		TempChanIDSeed: chanIDSeed,
+		ArbiterChan:      server.breachArbiter.newContracts,
+		SendToPeer:       server.SendToPeer,
+		NotifyWhenOnline: server.NotifyWhenOnline,
+		FindPeer:         server.FindPeer,
+		TempChanIDSeed:   chanIDSeed,
 		FindChannel: func(chanID lnwire.ChannelID) (*lnwallet.LightningChannel, error) {
 			dbChannels, err := chanDB.FetchAllChannels()
 			if err != nil {