暂时revert此处的优化

ios/Classes/Engine/FLBFlutterEngine.m

@@ -53,10 +53,10 @@
         }else{
             [_engine runWithEntrypoint:nil];
         }
-//        _dummy = [[FLBFlutterViewContainer alloc] initWithEngine:_engine
-//                                                          nibName:nil
-//                                                           bundle:nil];
-//        _dummy.name = kIgnoreMessageWithName;
+        _dummy = [[FLBFlutterViewContainer alloc] initWithEngine:_engine
+                                                          nibName:nil
+                                                           bundle:nil];
+        _dummy.name = kIgnoreMessageWithName;
     }
     
     return self;