Update rx_notifier.dart

fix refresh() not called when status equals to SuccessState

@@ -46,7 +46,6 @@ mixin StateMixin<T> on ListNotifier {
     _status = newStatus;
     _status = newStatus;
     if (newStatus is SuccessState<T>) {
     if (newStatus is SuccessState<T>) {
       _value = newStatus.data!;
       _value = newStatus.data!;
-      return;
     }
     }
     refresh();
     refresh();
   }
   }