1st attempt to fix opengl on ubuntu

xs/xsp/GUI_3DScene.xsp

@@ -190,11 +190,6 @@ remove_all_canvases()
     CODE:
         _3DScene::remove_all_canvases();
 
-void
-reset_current_canvas()
-    CODE:
-        _3DScene::reset_current_canvas();
-
 void
 set_active(canvas, active)
         SV   *canvas;