IKEv2 host-to-host with NAT and CP.

ikev2-hostpair-02 reconnects using the same IP, without sending any
deletes. It does this 4 times. Because no Initial Contact is used,
the old ipsec SA states linger around until expiry.

ikev2-hostpair-03-initial-contact uses Initial Contact where the
old IPsec SA states are properly removed.

While the old IPsec SA's are around, we should still have traffic
flow on the latest one, using the same re-obtained lease IP