[Mono-list] Access to (recent) older versions of mono in the download.mono-project.com debian repository

[Timotheus Pokorra]

> out deployment broke again :( ). I'm really happy to see new versions
> getting pushed, but we need to be able to make conscious decisions about
> if/when to upgrade.
You can comment the xamarin repo line in your /etc/apt sources list,
so that it will not check for new updates.