Typo fix in admin guide
Typo fix in admin guide

Change-Id: I0bc193766a3e135cde8da6c1c2ffd2a54c61a77a

AlekhyaMallina-Vedams/openstack-manuals,Akasurde/openstack-manuals,kairoaraujo/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals,gongysh2004/openstack-manual,openstack/openstack-manuals,gongysh2004/openstack-manual,Akasurde/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,potsmaster/openstack-manuals,openstack/openstack-manuals,saeki-masaki/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,potsmaster/openstack-manuals,saeki-masaki/openstack-manuals,kairoaraujo/openstack-manuals