Looks like requests to https://mozorg.cdn.mozilla.net/tabzilla/tabzilla.js with Accept-Language: fr,... 301 to e.g., https://mozorg.cdn.mozilla.net/fr/tabzilla/tabzilla.js. 

Let's make this `https://mozorg.cdn.mozilla.net/{{ request.locale }}/tabzilla/tabzilla.js` to avoid the extra redirect?