Please update linux-latest=63 for "stable-bpo"

[Teodor MICU <mteodor@gmail.com>]

Hi

I've noticed that linux-image-amd64 still depends on kernel
3.16-0.bpo.3. Because of this the latest kernel is not installed
automatically on dist-upgrade, thus many systems (ex. on gcloud) still
run the previous version (3.16.5~).

Thanks