keyboard: Try to parse keycodes better

gdk_keyval_from_name() doesn't seem to work as it used to.

https://bugzilla.gnome.org/show_bug.cgi?id=642489

panels/common/eggaccelerators.c

@@ -345,6 +345,9 @@ egg_accelerator_parse_virtual (const gchar            *accelerator,
 	}
       else
 	{
+	  if (g_str_has_prefix (accelerator, "0x"))
+	    keyval = 0;
+	  else
             keyval = gdk_keyval_from_name (accelerator);
 
           if (keyval == 0)