修改延迟加载脚本，defer只能在IE下生效，改为async

application/third_party/htmlcompressor/controllers/index.php

@@ -122,7 +122,7 @@ class Index extends CI_Controller {
 
             $js_content = $js_scr_content . $js_jquery_content;
             //延迟加载js，需要把返回的js代码保存到一个文件中，然后替换占位符，以便加载js文件
-            $lastload_js.='<script defer src="##DEFERSCRIPTDEFER##"></script>';
+            $lastload_js.='<script async="async" src="##DEFERSCRIPTDEFER##"></script>';
             $lastload_js.=$js_inline_content;
 
             $html_object = str_replace('</body>', $lastload_js . '</body>', $html_object);