Don't assume that KeySym is always defined as long in wxGTK.

Apparently this is not the case when using Wayland and using "%ld" to print it
out results in an assert failure.

Closes #15351.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74573 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/window.cpp

@@ -755,10 +755,10 @@ wxTranslateGTKKeyEventToWx(wxKeyEvent& event,
 
     KeySym keysym = gdk_event->keyval;
 
-    wxLogTrace(TRACE_KEYS, wxT("Key %s event: keysym = %ld"),
+    wxLogTrace(TRACE_KEYS, wxT("Key %s event: keysym = %lu"),
                event.GetEventType() == wxEVT_KEY_UP ? wxT("release")
                                                     : wxT("press"),
-               keysym);
+               static_cast<unsigned long>(keysym));
 
     long key_code = wxTranslateKeySymToWXKey(keysym, false /* !isChar */);