message: GnomePlugin now sets correct style based on theme variant
diff: #include <QMainWindow>
  #include <QAction>
  #include <QDebug>
  -#include <QGuiApplication>
  +#include <QApplication>
  +#include <QStyleFactory>
  GnomePlugin::GnomePlugin(QObject* parent) : QObject(parent)
  {
  @@ -93,6 +94,22 @@ void GnomePlugin::themeChanged(const ThemeInfo& theme)
  if (d.isRunningX11) {
  X11Helper::setWindowProperty(d.window->winId(), "_GTK_THEME_VARIANT", gtkThemeVariant);
  }
  +
  + QStyle *style;
  + if (theme.gtkThemeVariant() == "dark") {
  + style = QStyleFactory::create("adwaita-dark");
  + }
  + else {
  + style = QStyleFactory::create("adwaita");
  + }
  +
  + if (style) {
  + QApplication *app = static_cast<QApplication*>(QCoreApplication::instance());
  + app->setStyle(style);
  + }
  + else {
  + qWarning() << Q_FUNC_INFO << "The Adwaita Qt theme is not present on your system, please install it.";
  + }
  }
  void GnomePlugin::setupTrayIcon(QSystemTrayIcon* tray)
  