fixed: in ModelWrapper::clear_childs() childs_map.clear() was called in the loop, should be at the end

src/modelwrapper.h

@@ -99,9 +99,9 @@ public:
 				delete map_item.second;
 				map_item.second = nullptr;
 			}
-
-			childs_map.clear();
 		}
+
+		childs_map.clear();
 	}
 
 	virtual void add_child(const std::wstring & child_name, ModelWrapper * models_base)