convert error into warning

when using dev-server and an absolute URL for publicPath
to get webpack encore working in docker environment

lib/WebpackConfig.js

@@ -9,6 +9,7 @@
 
 'use strict';
 
+const chalk = require('chalk');
 const path = require('path');
 const fs = require('fs');
 
@@ -94,7 +95,8 @@ class WebpackConfig {
          */
         if (publicPath.includes('://')) {
             if (this.useDevServer()) {
-                throw new Error('You cannot pass an absolute URL to setPublicPath() and use the dev-server at the same time. Try using Encore.isProduction() to only configure your absolute publicPath for production.');
+                console.log(chalk.bgYellow.black(' WARNING ') + chalk.yellow(' You should not pass an absolute URL to setPublicPath() and use the dev-server at the same time'));
+                console.log();
             }
         } else {
             if (publicPath.indexOf('/') !== 0) {