Gui: solves #8939: timers are moved between non-QThreads

For more details see: https://github.com/FreeCAD/FreeCAD/issues/8939#issuecomment-1474888902

src/Gui/Tree.cpp

@@ -33,6 +33,7 @@
 # include <QMenu>
 # include <QMessageBox>
 # include <QPixmap>
+# include <QThread>
 # include <QTimer>
 # include <QToolTip>
 # include <QVBoxLayout>
@@ -757,6 +758,12 @@ void TreeWidget::updateStatus(bool delay) {
 }
 
 void TreeWidget::_updateStatus(bool delay) {
+    // When running from a different thread Qt will raise a warning
+    // when trying to start the QTimer
+    if (Q_UNLIKELY(thread() != QThread::currentThread())) {
+        return;
+    }
+
     if (!delay) {
         if (!ChangedObjects.empty() || !NewObjects.empty())
             onUpdateStatus();