no ipsec on cluster post NS mc's deletion during ipsecConfig mode `Full`, on an upgraded cluster from 4.14 ->4.15 build

 bot build on https://github.com/openshift/cluster-network-operator/pull/2191

    Always

Steps:
1. Cluster on EW+NS cluster(4.14), Upgraded to above bot build to check ipsecConfig modes 
2. ipsecConfig mode changed to Full
3. Deleted NS MCs 
4. new MCs spawned up as `80-ipsec-master-extensions` and `80-ipsec-worker-extensions`
5. cluster settled with no ipsec at all (no ovn-ipsec-host ds)
6. mode still Full

mode Full actually replicated Diasbled state on above steps    

Just NS IPsec should have gone away. EW should have persisted