remove "text/javascript" type from script type

To be compliant with HTML5

tarteaucitron.js

@@ -1586,7 +1586,6 @@ var tarteaucitron = {
             }
         } else {
             script = document.createElement('script');
-            script.type = 'text/javascript';
             script.id = (id !== undefined) ? id : '';
             script.async = true;
             script.src = url;