fix: 使用XEventMonitor接口错误

未清空保存的id，导致使用接口时报错

Log: 解决后端日志报错问题
Bug: https://pms.uniontech.com/zentao/bug-view-35358.html

frame/window/mainwindow.cpp

@@ -777,6 +777,8 @@ void MainWindow::updatePanelVisible()
         if (!m_registerKey.isEmpty()) {
             m_eventInter->UnregisterArea(m_registerKey);
             qDebug() << "register area clear";
+            //清空registerKey
+            m_registerKey.clear();
         }
         return expand();
     }

frame/window/mainwindow.h

@@ -127,8 +127,7 @@ private:
     DPlatformWindowHandle m_platformWindowHandle;
     DWindowManagerHelper *m_wmHelper;
     XEventMonitor *m_eventInter;
-    QString m_registerKey;
-
+    QString m_registerKey{""};
     QTimer *m_positionUpdateTimer;
     QTimer *m_expandDelayTimer;
     QTimer *m_leaveDelayTimer;