[Merge] ~schopin/livecd-rootfs:plucky-linux-sysctl-defaults into livecd-rootfs:ubuntu/master

[Simon Chopin]

> linux-sysctl-defaults should either be directly seeded or it should be a dependency of something. We should not hard code it in livecd-rootfs, particularly in such an opaque way. The fewer the package name references in livecd-rootfs the better.

Regardless of the seeded status of the package, the code is *still broken*! I don't know how badly it would fail if the package was a straight dependency of systemd or directly seeded, but that apt-get invocation would still attempt to remove it.
-- 
https://code.launchpad.net/~schopin/livecd-rootfs/+git/livecd-rootfs/+merge/477728
Your team Ubuntu Core Development Team is subscribed to branch livecd-rootfs:ubuntu/master.