system/skeleton: remove random-seed

Seeding the entropy pool with a known seed makes more harm than good. This is
especially bad for when /etc is not on a persistent writable storage, so the
entropy pool is seeded with the same value on every boot. Just drop it.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>