funding: make SendAnnouncement return error chan instead of error

server.go

@@ -738,11 +738,10 @@ func newServer(listenAddrs []net.Addr, chanDB *channeldb.DB, cc *chainControl,
 		CurrentNodeAnnouncement: func() (lnwire.NodeAnnouncement, error) {
 			return s.genNodeAnnouncement(true)
 		},
-		SendAnnouncement: func(msg lnwire.Message) error {
-			errChan := s.authGossiper.ProcessLocalAnnouncement(
+		SendAnnouncement: func(msg lnwire.Message) chan error {
+			return s.authGossiper.ProcessLocalAnnouncement(
 				msg, privKey.PubKey(),
 			)
-			return <-errChan
 		},
 		NotifyWhenOnline: s.NotifyWhenOnline,
 		TempChanIDSeed:   chanIDSeed,