Allow client to not send UUID
Allow client to not send UUID

If the client sends \0 instead of UUID, generate UUID on behalf of
client.

Signed-off-by: Magnus Skjegstad <9f4ca770b638615ac5c3e0d2da16b77c80c2f2c6@skjegstad.com>

djs55/vpnkit,djs55/vpnkit,djs55/vpnkit