Update plugin version in vue example

Author: artembatura

examples/modify-vue-files/package-lock.json

@@ -19,7 +19,7 @@
     "babel-eslint": "^10.1.0",
     "eslint": "^6.7.2",
     "eslint-plugin-vue": "^7.0.0",
-    "modify-source-webpack-plugin": "4.0.0-beta.2"
+    "modify-source-webpack-plugin": "4.0.1"
   },
   "eslintConfig": {
     "root": true,