Remove the ikev1 stub - Since I started iked, it has an empty privsep

Remove the ikev1 stub - Since I started iked, it has an empty privsep
process for ISAKMP+IKEv1.  I kept it to let somebody either contribute
the old protocol one day, I never intended to implement IKEv1 myself,
or to add a new kind of pipe to isakmpd to hand off IKEv1 messages.
As IKEv2 is widely supported by all major OS and networking vendors
now, I'm happy to scrap the idea of supporting ISAKMP+IKEv1.  It is
still possible to use isakmpd for legacy VPNs.

OK mikeb@