RFC 7427 :
Basic pluto with IKEv2 using X.509 on the responder (east), and Strongswan on
the initiator (west) with impairment.

The impairment is introduced in such a way that we ignore processing the hash notify
we receive from strongswan in IKE_SA_INIT Request.

This is to ensure that Libreswan with default Authentication type as 
Digital Signatures (RFC 7427 )can still interop with an older version of strongswan that does not 
support RFC 7427



