Bug 1014823 - Redirect /.+/firefox/releases/whatsnew/ (404) to /firefox/...

...whatsnew/
Instead of listing each locale, it's better to use the common regex. I think you just want something like:

`^/(\w{2,3}(?:-\w{2})?/)?/firefox/releases/whatsnew(/?)$`

Also, [the bug](https://bugzilla.mozilla.org/show_bug.cgi?id=1014823#c0) requests the redirect go to `/firefox/whatsnew` (not `/firefox/new`).