message: Fix broken notificator on GNOME
  That bug was introduced in
diff: @@ -130,6 +130,7 @@ BitcoinGUI::BitcoinGUI(interfaces::Node& node, const PlatformStyle *_platformSty
  if (QSystemTrayIcon::isSystemTrayAvailable()) {
  createTrayIcon(networkStyle);
  }
  + notificator = new Notificator(QApplication::applicationName(), trayIcon, this);
  // Create status bar
  statusBar();
  @@ -537,8 +538,7 @@ void BitcoinGUI::setClientModel(ClientModel *_clientModel)
  unitDisplayControl->setOptionsModel(_clientModel->getOptionsModel());
  OptionsModel* optionsModel = _clientModel->getOptionsModel();
  - if(optionsModel)
  - {
  + if (optionsModel && trayIcon) {
  // be aware of the tray icon disable state change reported by the OptionsModel object.
  connect(optionsModel, &OptionsModel::hideTrayIconChanged, this, &BitcoinGUI::setTrayIconVisible);
  @@ -643,14 +643,10 @@ void BitcoinGUI::createTrayIcon(const NetworkStyle *networkStyle)
  assert(QSystemTrayIcon::isSystemTrayAvailable());
  #ifndef Q_OS_MAC
  - trayIcon = new QSystemTrayIcon(this);
  + trayIcon = new QSystemTrayIcon(networkStyle->getTrayAndWindowIcon(), this);
  QString toolTip = tr("%1 client").arg(tr(PACKAGE_NAME)) + " " + networkStyle->getTitleAddText();
  trayIcon->setToolTip(toolTip);
  - trayIcon->setIcon(networkStyle->getTrayAndWindowIcon());
  - trayIcon->hide();
  #endif
  -
  - notificator = new Notificator(QApplication::applicationName(), trayIcon, this);
  }
  void BitcoinGUI::createTrayIconMenu()
  