@https://www.keycdn.com/blog/google-pagespeed-insights-wordpress/:
Another issue we run into is with Google Analytics. Funny thing is that this is a warning from their own script. http://www.google-analytics.com/analytics.js. The problem occurs because their script has a cache lifetime of only 2 hours. Google has already said that they won’t fix this. Which leaves almost everyone running analytics with a warning that they cannot fix. The most frustrating part of this is probably for people that deal with clients asking for Google PageSpeed Insights improvements. Telling a client you can’t fix something because Google won’t let you in their own tool sounds a little crazy.