Bug#869694: nvidia-driver: Installing the nvidia-340 package on stretech is impossible, nvidia-375 will be installed instead

[Herr Oswald]

> cannot reproduce in a fresh Stretch chroot. All the correct packages
> are installed.
> 
> Are you sure you don't have previously installed leftovers?

No, I'm not. I did "apt-get purge nvidia*", but that seems not to have
been enough. What shall I do?

I came with an upgrade from 8.9, but was puzzled that after the upgrade
I still had the 3.16 kernel which I had before. So I upgraded that
manually to 4.9. Maybe I broke something on that way?

Cheers,
herrdeh