Fix webpackConfig import

Author: ahangarha

test/dummy/config/webpack/webpack.config.js

@@ -1,15 +1,15 @@
 const { existsSync } = require('fs');
 const { resolve } = require('path');
-const { env, webpackConfig } = require('shakapacker');
+const { env, generatewebpackConfig } = require('shakapacker');
 
 const envSpecificConfig = () => {
   const path = resolve(__dirname, `${env.nodeEnv}.js`);
   if (existsSync(path)) {
     console.log(`Loading ENV specific webpack configuration file ${path}`);
     return require(path);
   } else {
-    return webpackConfig;
+    return generatewebpackConfig();
   }
 };
 
-module.exports = envSpecificConfig();
+module.exports = envSpecificConfig();