图表toggle样式调整

src/themes/default/chartdesigner.less

@@ -11,9 +11,6 @@
                 background: @sider-background-color;
                 border: none;
                 &> .ant-layout-sider-children {
-                    >.collapse-toggle {
-                        color: blue;
-                    }
                     >.ant-tabs {
                         >.ant-tabs-bar {
                             border: none;