XCB: Update the high DPI scaling in more conditions

I don't think fae8ee8b42 was enough. I've
started getting small fonts in Qt Creator under some other
circumstances.

Change-Id: I1cc7601489634e96833cfffd1456caea823aa84a
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

src/plugins/platforms/xcb/qxcbconnection.cpp

@@ -258,8 +258,8 @@ void QXcbConnection::updateScreens(const xcb_randr_notify_event_t *event)
                 } else {
                     screen = createScreen(virtualDesktop, output, outputInfo.data());
                     qCDebug(lcQpaScreen) << "output" << screen->name() << "is connected and enabled";
-                    QHighDpiScaling::updateHighDpiScaling();
                 }
+                QHighDpiScaling::updateHighDpiScaling();
             }
         } else if (screen) {
             if (output.crtc == XCB_NONE && output.mode == XCB_NONE) {