Fix some harmless unused parameter warnings.

These warnings only happen in specific builds (when HAVE_LANGINFO_H and
wxUSE_DISPLAY are undefined/off).

See #11817.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@63720 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/stc/PlatWX.cpp

@@ -753,6 +753,8 @@ PRectangle Window::GetMonitorRect(Point pt) {
     int n = wxDisplay::GetFromPoint(wxPoint(pt.x, pt.y));
     wxDisplay dpy(n == wxNOT_FOUND ? 0 : n);
     rect = dpy.GetGeometry();
+#else
+    wxUnusedVar(pt);
 #endif
     return PRectangleFromwxRect(rect);
 }