th script async fail to be verificate into webmaster tool site owner

[GoogleCodeExporter]

hello i'm using the new script version for modern browser as suggested by 
google analytics doc so the code into header page  is :

<script>
    window.ga=window.ga||function(){(ga.q=ga.q||[]).push(arguments)};ga.l=+new Date;
    ga('create', 'UA-.....', 'auto');
    ga('set', 'anonymizeIp', true);
    ga('send', 'pageview');
</script>
<script async src='//www.google-analytics.com/analytics.js'>
</script>

but now it fail to validate into webmaster tool asking the validate by google 
analytics tag

Original issue reported on code.google.com by francesc...@gmail.com on 15 Feb 2016 at 3:27