loadbalancer: remove controller_host
loadbalancer: remove controller_host

controller_host was deprecated and is not used anymore anywhere.
Let's drop it.
Also make controller_hosts really required, by not setting a default
paramter, so Puppet catalog will fail if no value is given.

Change-Id: Iad760115f925e848e4b72009db5177f88ceb4ad8

openstack/puppet-tripleo,openstack/puppet-tripleo,openstack/puppet-tripleo