Provide backwards compatibility for security_groups_driver
Provide backwards compatibility for security_groups_driver

Adds 'icmpv6' to the protocol map for the security groups driver.

The Neutron Controller (Liberty) is sending rules with the
protocol 'icmpv6', while newer releases are sending rules
with 'ipv6-icmp'.

Co-Authored-By: Claudiu Belu <cbelu@cloudbasesolutions.com>

Change-Id: Ife417e878890134a608bd8fc531b8ed0d7f1a829
Closes-Bug: #1586362

openstack/networking-hyperv,openstack/networking-hyperv,gabriel-samfira/networking-hyperv,stackforge/networking-hyperv,cloudbase/networking-hyperv