message: Hide most of the stacked widget warnings (linux)
  One of them is still left but it is benign
diff: @@ -80,13 +80,18 @@ void IdleNotificationWidget::idleHintReceived(QDBusPendingCallWatcher *watcher)
  void IdleNotificationWidget::display() {
  auto sw = qobject_cast<QStackedWidget*>(parent());
  + if (sw->currentIndex() >= 0)
  previousView = sw->currentWidget();
  + else
  + previousView = nullptr;
  sw->setCurrentWidget(this);
  }
  void IdleNotificationWidget::hide() {
  - if (previousView)
  + if (previousView) {
  qobject_cast<QStackedWidget*>(parent())->setCurrentWidget(previousView);
  + previousView = nullptr;
  + }
  }
  IdleNotificationWidget::~IdleNotificationWidget() {
  