mention the final ocata osc version in releasenotes
mention the final ocata osc version in releasenotes

we neglected to add the final osc version in our release note
page, it should be 3.8.1

Change-Id: I4291a09924ce8beb29c8c3aff18962a43f0241b0

openstack/python-openstackclient,dtroyer/python-openstackclient,dtroyer/python-openstackclient,openstack/python-openstackclient