remove all async_start/end calls

src/node_panel_brush.cpp

@@ -102,7 +102,6 @@ void NodePanelBrush::init()
                 //auto po2 = img.resize_power2();
                 img.save(path_high);
 
-                async_start();
                 NodeButtonBrush* brush = new NodeButtonBrush;
                 m_container->add_child(brush);
                 brush->init();
@@ -114,8 +113,6 @@ void NodePanelBrush::init()
                 brush->brush_name = name;
                 brush->m_user_brush = true;
                 brush->on_click = std::bind(&NodePanelBrush::handle_click, this, std::placeholders::_1);
-                app_redraw();
-                async_end();
                 save();
             }
         });