It wasn't explicitly mentioned in that ticket, but we should probably drop "All rights reserved" since that's not true. The content is under CC BY-SA 4.0 except in cases where there's an explicit use of another license.

I suggest something like

Copyright &copy; Copyright Fedora Project Contributors. Licensed <a href="https://creativecommons.org/licenses/by-sa/4.0/legalcode">CC BY-SA 4.0</a> except where noted.

Thoughts, @richardfontana?

I prefer "Licensed under . . . " but otherwise looks OK.

So this is the final text ?

Copyright &copy; Copyright Fedora Project Contributors. Licensed under <a href="https://creativecommons.org/licenses/by-sa/4.0/legalcode">CC BY-SA 4.0</a> except where noted.

I'm not sure what's the use for this file (static/firefox/index.html) but this is not the right one to edit.
You're looking for data/templates/footer.html instead.

Is this PR relevant anymore @thunderbirdtr @darknao?

The text is correct but the modified files are not the correct ones.
Let's close it.