RFC: disable haproxy http mode

In some cases the http mode in haproxy causes issues with api calls
(We exeperienced this in production between horizon and neutron)

See:
https://ask.openstack.org/en/question/57958/keystone-through-haproxy/

Change-Id: Id2079c5a491ef8691e7ad8846a5fec99e49ec4ba

ansible/roles/haproxy/templates/haproxy.cfg.j2

@@ -15,7 +15,6 @@ global
 
 defaults
   log global
-  mode http
   option redispatch
   option httplog
   option forwardfor