fix: 修复任务栏崩溃的问题

任务栏连续崩溃三次,会进入安全模式,不加载插件部分,这是表象,实际就是崩溃了

Log: 修复一处崩溃问题
Bug: https://pms.uniontech.com/zentao/bug-view-41100.html
Change-Id: I272b6181ce572355c86daa7c062653f71fbf34d1
Reviewed-on: http://gerrit.uniontech.com/c/dde-dock/+/1217
Reviewed-by: <mailman@uniontech.com>
Reviewed-by: fanpengcheng <fanpengcheng@uniontech.com>
Reviewed-by: niecheng <niecheng@uniontech.com>
Tested-by: <mailman@uniontech.com>

frame/controller/dockitemmanager.cpp

@@ -224,6 +224,7 @@ void DockItemManager::appItemRemoved(const QString &appId)
         }
         if (!app->isValid() || app->appId() == appId) {
             appItemRemoved(app);
+            break;
         }
     }