move config where it is due

Author: Barthélémy Ledoux

babel.rollup.js

@@ -1,3 +1,3 @@
 module.exports = {
-  presets: ["@vue/app"]
+  presets: [["@vue/app", { useBuiltIns: false }]]
 };

rollup.config.js

@@ -24,9 +24,8 @@ export default {
     commonjs(),
     babel({
       babelrc: false,
-      // avoid using babel.config.js that kills es6 modules for ie compatibility
+      // avoid using babel.config.js. It kills es6 modules for ie compatibility
       configFile: "./babel.rollup.js",
-      presets: [["@vue/babel-preset-app", { useBuiltIns: false }]],
       extensions: [".js"],
       runtimeHelpers: true
     }),