为什么webpack在打包html下的img时被打包了两次，一个文件有效一个无效？

const { resolve } = require('path')
const HtmlWebpackPlugin = require('html-webpack-plugin')

module.exports = {
    entry: './src/index.js',
    output: {
        filename: 'built.js',
        path: resolve(__dirname, 'build')
    },
    module: {
        rules:[
            {//css
                test: /\.css$/,
                use:[
                    'style-loader',
                    'css-loader'
                ]
            },
            {//less
                test: /\.less$/,
                use:[
                    'style-loader',
                    'css-loader',
                    'less-loader'
                ]
            },
            {
                test:/\.(jpg|png|gif)$/,
                loader:'url-loader',
                options:{
                    limit: 8 * 1024,
                }
            },
            {
                test:/\.html$/,
                loader: 'html-loader'
            }
        ]
    },
    plugins: [
        new HtmlWebpackPlugin({
            template: './src/index.html'
        })
    ],
    mode: 'development',
}