[install-guide] fixed directory read-write permissions
[install-guide] fixed directory read-write permissions

Change-Id: I805758f781247621e561689f76f7a9d5e49fc70c
Closes-Bug: #1569878

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