Change haproxy variable used to set security headers to haproxy_frontend_raw
Change haproxy variable used to set security headers to haproxy_frontend_raw

Haproxy role has changed the naming of ``haproxy_raw`` to
 ``haproxy_frontend_raw``

Change-Id: I6561ef28831f55490e742b371bdccd0ecd2fd113

stackforge/os-ansible-deployment,openstack/openstack-ansible,openstack/openstack-ansible,stackforge/os-ansible-deployment