Unable to add a ServerPackages

Hi ! 

i'm trying to add a "ServerPackages=" line in UnrealTournament.ini.

So I'm doing the following : 

- Turning off the docker
- Adding my line
- Turning it on

After the restart, the line I've added in UnrealTournament.ini is erased, and if I ssh into the container, I can't see it either in the UnrealTournament.ini file.

Am I doing something wrong ?

Thanks