fluid: Don't call obsolete Fl::scheme().

fluid/fluid.cxx

@@ -1739,25 +1739,8 @@ extern void fill_in_New_Menu();
 void scheme_cb(Fl_Choice *, void *) {
   if (compile_only)
     return;
-
-  switch (scheme_choice->value()) {
-    case 0 : // Default
-      Fl::scheme(NULL);
-      break;
-    case 1 : // None
-      Fl::scheme("none");
-      break;
-    case 2 : // Plastic
-      Fl::scheme("plastic");
-      break;
-    case 3 : // GTK+
-      Fl::scheme("gtk+");
-      break;
   }
 
-  fluid_prefs.set("scheme", scheme_choice->value());
-}
-
 void toggle_widgetbin_cb(Fl_Widget *, void *) {
   if (!widgetbin_panel) {
     make_widgetbin();