bug#40097: 28.0.50; Preferred font ignored for specific charset

[Eli Zaretskii]

> From: Robert Pluim <rpluim@gmail.com>
> Cc: sorganov@gmail.com,  40097@debbugs.gnu.org
> Date: Wed, 18 Mar 2020 21:47:19 +0100
> 
>     >> So correcting the name of the registry in ftfont.c fixes this.
> 
>     Eli> You mean, fixing that makes DejaVu Sans Mono be used in this case?
> 
> Yes.
> 
>     Eli> That's great, let's fix this in emacs-27 then.
> 
> If you want me to be conservative, I could *add* a microsoft-cp1251
> entry instead of replacing windows-1251, but as far as I know
> windows-1251 is not a valid registry name.

I see no need to add it, this registry value cannot be used much, or
we'd have many bug reports about this problem long ago.  Let's just
replace the incorrect value with the correct one.

Thanks.