multi: rename ChannelUpdate to ChannelUpdate1

In preparation for adding a new ChannelUpdate2 message and a
ChannelUpdate interface, we rename the existing message to
ChannelUpdate1.

netann/chan_status_manager.go

@@ -60,7 +60,7 @@ type ChanStatusConfig struct {
 	// ApplyChannelUpdate processes new ChannelUpdates signed by our node by
 	// updating our local routing table and broadcasting the update to our
 	// peers.
-	ApplyChannelUpdate func(*lnwire.ChannelUpdate, *wire.OutPoint,
+	ApplyChannelUpdate func(*lnwire.ChannelUpdate1, *wire.OutPoint,
 		bool) error
 
 	// DB stores the set of channels that are to be monitored.
@@ -650,7 +650,7 @@ func (m *ChanStatusManager) signAndSendNextUpdate(outpoint wire.OutPoint,
 // in case our ChannelEdgePolicy is not found in the database. Also returns if
 // the channel is private by checking AuthProof for nil.
 func (m *ChanStatusManager) fetchLastChanUpdateByOutPoint(op wire.OutPoint) (
-	*lnwire.ChannelUpdate, bool, error) {
+	*lnwire.ChannelUpdate1, bool, error) {
 
 	// Get the edge info and policies for this channel from the graph.
 	info, edge1, edge2, err := m.cfg.Graph.FetchChannelEdgesByOutpoint(&op)