Removes /havana/ links from landing page
Removes /havana/ links from landing page

They didn't build correctly after cutting a branch named
nearly/havana so we'll revisit in the morning.

Change-Id: I044e229f39d3259ef4ccdeee8b66e1cfcd29aa1a

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