[Dev] [PATCH] WIP Iceweasel update to 75.0-1

[bill-auger]

if you guys have the time, could you look into the problem with
the language packs for this iteration? - i suspect that the
problem is not actually in the language packs; but needs to be
addressed in the browser or branding - there is apparently some
GUI element that is not exposed, or is not branded properly - i
think it is related to the firefox sync login

https://labs.parabola.nu/issues/2571