Correct the 'Admin Guide' title name
Correct the 'Admin Guide' title name

Since Mitaka reorganised the Admin User Guide content together with the
Cloud Admin Guide content to create a new Administrator Guide. So the
title should be "OpenStack Administrator Guide". Refer to
'http://docs.openstack.org/releasenotes/openstack-manuals/mitaka.html#user-guides'

Change-Id: Ic0b8e8defe5942dd1e6ca50a7af13708c5653166

AlekhyaMallina-Vedams/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,openstack/openstack-manuals