fix #877

Author: LinusBorg

template/build/dev-server.js

@@ -10,7 +10,7 @@ var path = require('path')
 var express = require('express')
 var webpack = require('webpack')
 var proxyMiddleware = require('http-proxy-middleware')
-var webpackConfig = {{#if_or unit e2e}}process.env.NODE_ENV === 'testing' || 'production'
+var webpackConfig = {{#if_or unit e2e}}(process.env.NODE_ENV === 'testing' || process.env.NODE_ENV === 'production')
   ? require('./webpack.prod.conf')
   : {{/if_or}}require('./webpack.dev.conf')