IKEv1 ipsec-interface needing lease but skipping MODE_CFG

This means that the Quick Mode exchange is responsible for updating
policy and obtaining the lease.

In both 4.x and 5.0, the Quick Mode code bumbled a check and
determined that the connection was in TRANSPORT_MODE, and, hence, the
child's selectors were fine (no lease required).  Consequently, what
evern was in the connection was installed as policy.

- in 4.x, the connection was instantiated with the child selectors set

- in 5.0, the policy was left unset

See github:

  Version 5.x: xfrmi+xauth+modecfg+addresspool: server overwrites
  default route when the client don't use modecfg #1955

Test from Wolfgang.
