notification: bring window to front when clicked

Bringing Ring's window to front when clicking on an incoming message
notification was only working in the case where the window was
minimized. It is now also working when it is just left behind another
application.

Change-Id: I777a0eb74f3534fa8b538379ae43e59681801df5
Reviewed-by: Olivier Soldano <olivier.soldano@savoirfairelinux.com>
Tuleap: #926

mainwindow.cpp

@@ -174,6 +174,8 @@ MainWindow::trayActivated(QSystemTrayIcon::ActivationReason reason)
 void
 MainWindow::notificationClicked() {
     showNormal();
+    activateWindow();
+    raise();
 }
 
 void