bug#44020: 28.0.50; Prefer selection of colour emoji fonts?

[Eli Zaretskii]

> From: Robert Pluim <rpluim@gmail.com>
> Cc: 44020@debbugs.gnu.org,  larsi@gnus.org,  Stephen Berman
>  <stephen.berman@gmx.net>
> Date: Tue, 20 Oct 2020 10:58:31 +0200
> 
> So it was failing on Debian as well, until I deleted my
> ~/.config/fontconfig directory, which ended up fixing it on Ubuntu as
> well.

This Fontconfig cache thingy appears in too many trouble reports.
Sounds like something we should ask users to do up front whenever they
report some weird font-related issue.