OS specific download page always downloads Firefox for current OS

[yoasif]

Description

Noticed that the OS specific download pages always download Firefox for Linux (on my Linux machine).

Steps to reproduce

1. Navigate to one of: https://www.mozilla.org/en-US/firefox/windows/ https://www.mozilla.org/en-US/firefox/browsers/windows-64-bit/ https://www.mozilla.org/en-US/firefox/mac/ https://www.mozilla.org/en-US/firefox/browsers/chromebook/
2. Click "Download Now"

Expected result

The OS specific file should download.

Actual result

I always get the Linux version.

Environment

Firefox Nightly on Linux.