title: 404 because of restarting the webpack-dev-server
body: <p>I'm getting this in my developer tools when I try change my react component and save it to see if hot loader updated my page:</p>
  
  <pre><code>GET http://localhost:3000/public/bundle/76566a1ad7e45b834d4e.hot-update.json 404 (Not Found)hotDownloadManifest @ main.js:26hotCheck @ main.js:210check @ main.js:9288(anonymous function) @ main.js:9346
  main.js:9303 [HMR] Cannot find update. Need to do a full reload!
  main.js:9304 [HMR] (Probably because of restarting the webpack-dev-server)
  </code></pre>
  
  <p>I'm not sure why this is occurring. I am trying to run django as my backend server (<a href="https://webpack.github.io/docs/webpack-dev-server.html#combining-with-an-existing-server">webpack instructions</a>)</p>
  
  <p>Here is my webpack.watch.js:</p>
  
  <pre><code>var path = require('path');
  var config = require("./webpack.config.js");
  var Webpack = require("webpack");
  var ExtractTextPlugin = require("extract-text-webpack-plugin");
  
  var port = process.env.WEBPACK_PORT || 3000;
  var host = process.env.HOST || 'localhost';
  
  config.entry.unshift(
      "webpack-dev-server/client?http://" + host + ":" + port,
      "webpack/hot/only-dev-server"   // only prevents reload on syntax errors
  );
  
  config.plugins = [
      new Webpack.HotModuleReplacementPlugin(),
      new Webpack.NoErrorsPlugin(), // don't reload if there is an error
      new ExtractTextPlugin("style.css", {
          allChunks: true
      })
  ];
  
  config.module.loaders = [
      { test: /\.css$/, exclude: /node_modules/, loader: ExtractTextPlugin.extract('style-loader', 'css-loader') },
      { test: /\.json$/, loader: 'json-loader' },
      { test: /\.jsx$/, loaders: ['react-hot', 'babel-loader'], include: path.join(__dirname, 'app') },
      { test: /\.es6$/, exclude: /node_modules/, loader: 'babel-loader?stage=0&amp;optional=runtime'},
      { test: /\.js$/, exclude: /node_modules/, loader: 'babel-loader?stage=0&amp;optional=runtime'},
      { test: /\.scss$/, exclude: /node_modules/, loaders: ExtractTextPlugin.extract('style-loader', 'css-loader!sass-loader') }
  ];
  
  config.devServer = {
      publicPath:  config.output.publicPath,
      filename: 'main.js',
      contentBase: './public',
      hot:         true,
      // Make connection between webpack-dev-server and its runtime set inline: true
      inline:      true,
      lazy:        false,
      quiet:       true,
      noInfo:      true,
      headers:     {"Access-Control-Allow-Origin": "*"},
      stats:       {colors: true},
  
      // webpack-dev-server will serve built/bundled static files from host:port
      host:        "0.0.0.0",
      port:        port
  };
  
  module.exports = config;
  </code></pre>
  
  <p>Here is my webpack.config.js:</p>
  
  <pre><code>module.exports = {
      entry: [
          './app/index.js'
      ],
  
      output: {
          path: './public/bundle',
          filename: 'main.js',
          publicPath: 'http://localhost:3000/public/bundle/'
      },
  
      plugins: [
          new BundleTracker({filename: './webpack-stats.json'}),
      ],
  
      module: {
          loaders: [
              { test: /\.css$/, exclude: /node_modules/, loader: ExtractTextPlugin.extract('style-loader', 'css-loader') },
              { test: /\.json$/, loader: 'json-loader' },
              { test: /\.jsx$/, loaders: ['react-hot', 'babel-loader'], include: path.join(__dirname, 'app') },
              { test: /\.es6$/, exclude: /node_modules/, loader: 'babel-loader?stage=0&amp;optional=runtime'},
              { test: /\.js$/, exclude: /node_modules/, loader: 'babel-loader?stage=0&amp;optional=runtime'},
              { test: /\.scss$/, exclude: /node_modules/, loaders: ExtractTextPlugin.extract('style-loader', 'css-loader!sass-loader') }
          ]
      },
  }
  </code></pre>