We've recently published reports with broken links and reports
that simply broke the build of the website. Let's try harder to notice that
before publishing.

That is, add a valid one if needed, and if there's one already, check that
it's valid.

I've noticed I'm doing this manually all the time as a sanity check
so let's automate this step.

Setting this variable has lots of side effects we can do without.

This is a test commit for testing a script on the weblate VM. I'm not able to do that without going through the real process.

The previous formatting suggested that the whole file was required,
which is wrong.

… just like we do for Tor Browser.

Having this kind of stuff in /etc/skel makes it harder for us to
handle upgrades.

Enigmail commit d2a0c88d21a5e4f7ca76e7a1e9e50345e973da70 (part of 2.0~beta1 and
newer) renamed the pref and removed all usage of the old one.

On the Torbirdy front nothing happened yet to adjust to this change; let's
assume that they'll do s/protectHeaders/protectedHeaders/ too and turn the pref
into an integer (1: default: ask user at 1st time use / 0: off / 2: on) as well.
When we'll upgrade Torbirdy I'll check this (refs: #15661).