fix: compile error when updating less-loader to v6 (#2194)

Author: starkfire

package.json

@@ -121,7 +121,7 @@
         "json-templater": "^1.2.0",
         "jsonp": "^0.2.1",
         "less": "^3.9.0",
-        "less-loader": "^5.0.0",
+        "less-loader": "^6.0.0",
         "less-plugin-npm-import": "^2.1.0",
         "lint-staged": "^10.0.0",
         "marked": "0.3.18",

webpack.config.js

@@ -59,7 +59,15 @@ module.exports = {
             loader: 'css-loader',
             options: { sourceMap: true },
           },
-          { loader: 'less-loader', options: { sourceMap: true, javascriptEnabled: true } },
+          {
+            loader: 'less-loader',
+            options: {
+              lessOptions: {
+                sourceMap: true,
+                javascriptEnabled: true,
+              },
+            },
+          },
         ],
       },
       {