[packman] Extra: Please add missing macro in Project Config

[Maurizio Galli]

Hello,
Extra currently does not have any macro defined in Project Config.
This breaks the functionality of bcond for the proper building of
Discord. Could someone please add the following to Extra in Project
Config:

Macros:
%define _with_ffmpeg 1
:Macros

Thank you so much.
Cheers,

Maurizio Galli