[api-ref]Openswan/Libreswan: support sha256 for auth algorithm

[OpenStack Infra]

https://review.openstack.org/303684
Dear bug triager. This bug was created since a commit was marked with DOCIMPACT.

commit b73e1002555cfa70ccfea8ffe685672c0b679212
Author: nick.zhuyj <email address hidden>
Date: Fri Apr 8 23:48:33 2016 -0500

    Openswan/Libreswan: support sha256 for auth algorithm

    Add support for sha256 as it is requirement from customer.
    Currently, there is no ike/esp fields in strongswan ipsec.conf
    template, so by default. sha256 is used. But for openswan auth
    algorithm is get from configuration, so only sha1 is supported.
    This patch enable Openswan/Libreswan to support sha256.

    Note: this change is DocImpact and APIImpact

    Change-Id: I02c80ec3494eb0edef2fdaa5d21ca0c3bbcacac2
    Closes-Bug: #1567846

[Atsushi SAKAI (sakaia)]

neutron vpnaas section need describe.

[Boden R (boden)]

sha256 has already been added to the API ref [1].
Marking as invalid.

[1] https://developer.openstack.org/api-ref/networking/v2/?expanded=show-ipsec-policy-detail