Set the browser header for the first ESR 60 based alpha to be the same as ESR 52
When the first ESR 60 based alpha is released, ESR 52 is still used for the stable release, and so this makes the TB alpha users more fingerprintable during that period.
Solution: Set the browser header for the first ESR 60 based alpha to be the same as ESR 52 before the release of the first ESR 60 based TB stable.