fundingmanager+lnd: remove no longer needed FindPeer and SendToPeer

callbacks

The FindPeer and SendToPeer callbacks are no longer needed within the
fundingManager due to the previous commit allowing us to send messages
to peers directly.

lnd.go

@@ -360,9 +360,7 @@ func lndMain() error {
 				idPrivKey.PubKey())
 			return <-errChan
 		},
-		SendToPeer:       server.SendToPeer,
 		NotifyWhenOnline: server.NotifyWhenOnline,
-		FindPeer:         server.FindPeer,
 		TempChanIDSeed:   chanIDSeed,
 		FindChannel: func(chanID lnwire.ChannelID) (*lnwallet.LightningChannel, error) {
 			dbChannels, err := chanDB.FetchAllChannels()