Cleanup horizon vars in hosts.yml
Cleanup horizon vars in hosts.yml

This patch cleans up the horizon variables in hosts.yml:

  * Simplifies Jinja logic for variables
  * Removes LBaaS v1 from horizon_enable_neutron_lbaas
  * Adds LBaaS v2 to horizon_enable_neutron_lbaas

Change-Id: I508f523dcbc0dcf7d9280ad8d6173526c289d686

yanyao/openstack-ansible,BjoernT/openstack-ansible,stackforge/os-ansible-deployment,BjoernT/os-ansible-deployment,Logan2211/openstack-ansible,weezer/openstack-ansible,mancdaz/openstack-ansible,yanyao/newton,openstack/openstack-ansible,yanyao/openstack-ansible,cloudnull/os-ansible-deployment,bunchc/openstack-ansible,bunchc/openstack-ansible,BjoernT/os-ansible-deployment,weezer/openstack-ansible,mancdaz/openstack-ansible,robb-romans/openstack-ansible,robb-romans/openstack-ansible,os-cloud/os-ansible-deployment,openstack/openstack-ansible,stackforge/os-ansible-deployment,cfarquhar/openstack-ansible,os-cloud/os-ansible-deployment,yanyao/newton,cloudnull/os-ansible-deployment,Logan2211/openstack-ansible,BjoernT/os-ansible-deployment,BjoernT/openstack-ansible,cfarquhar/openstack-ansible