title: MiniCssExtractPlugin not working with hash as parameter
body: <p>I am using <strong><code>MiniCssExtractPlugin</code></strong> as CSS minifier.</p>
  
  <p>The CSS file is used on the external project, and in that reason, I need to use the hash as a parameter. </p>
  
  <p>I hash is part of file name then everything working fine. 
  example      </p>
  
  <pre><code>plugins.push(
      new MiniCssExtractPlugin({
        filename: '[name].[hash:4].css',
      })
    );
  </code></pre>
  
  <p>but if the hash is passed as a parameter  </p>
  
  <pre><code>plugins.push(
      new MiniCssExtractPlugin({
        filename: '[name].css?[hash:4]',
      })
    );
  </code></pre>
  
  <p>The file would be generated but not minified.</p>
  
  <pre><code> rules.push(
      {
        test: /\.css$/,
        exclude: paths.navigation,
        use: [
          'style-loader',
          'css-loader',
          'sass-loader',
          'postcss-loader',
        ],
      }
    );
  </code></pre>