[install] Fix the incorrect description
[install] Fix the incorrect description

backport: mitaka

Change-Id: I64c49039ae5c7685cc62dfbf41b00123d3cf24e6
Closes-Bug: #1600434

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