[install-guide] Fix typo
[install-guide] Fix typo

Change-Id: I29d481277996fc5dc7fee1f965f06d6f227e0bbc

kairoaraujo/openstack-manuals,potsmaster/openstack-manuals,saeki-masaki/openstack-manuals,openstack/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,Akasurde/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,kairoaraujo/openstack-manuals,Akasurde/openstack-manuals,openstack/openstack-manuals,saeki-masaki/openstack-manuals,openstack/openstack-manuals,potsmaster/openstack-manuals,openstack/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals