watchtower/multi: define AltruistSessions feature bit as 0/1

watchtower/wtserver/server.go

@@ -92,7 +92,7 @@ type Server struct {
 // sessions and send state updates.
 func New(cfg *Config) (*Server, error) {
 	localInit := wtwire.NewInitMessage(
-		lnwire.NewRawFeatureVector(wtwire.WtSessionsOptional),
+		lnwire.NewRawFeatureVector(wtwire.AltruistSessionsOptional),
 		cfg.ChainHash,
 	)