规范任务栏代码，增加代码整洁度和安全性

Log: 规范任务栏模块代码
Task: https://pms.uniontech.com/task-view-150885.html
Influence: 无
Change-Id: I385fbb71cf4c1408ffd4c6684128b412a187ab28

src/modules/dock/appmenu.cpp

@@ -81,7 +81,7 @@ QString AppMenu::getMenuJsonStr()
         objItem["itemIconInactive"] = item.iconInactive;
         objItem["showCheckMark"] = item.showCheckMark;
         objItem["itemSubMenu"] = item.subMenu ? item.subMenu->getMenuJsonStr() : "";
-        array.push_back(QJsonValue(objItem));
+        array.push_back(objItem);
     }
     obj["items"] = QJsonValue(array);
     obj["checkableMenu"] = checkableMenu;