support calling multiple webhook urls

notifications/notification_service.go

@@ -44,6 +44,8 @@ func (s *NotificationService) Notify(
 		},
 	}
 
+	notified := false
+	for _, r := range registrations {
 		var buf bytes.Buffer
 		err = json.NewEncoder(&buf).Encode(req)
 		if err != nil {
@@ -51,8 +53,6 @@ func (s *NotificationService) Notify(
 			return false, err
 		}
 
-	notified := false
-	for _, r := range registrations {
 		resp, err := http.DefaultClient.Post(r, "application/json", &buf)
 		if err != nil {
 			log.Printf("Failed to send payment notification for %s to %s: %v", pubkey, r, err)