loadbalancer: revert service_manage for haproxy

We need to manage the service, otherwise each time Puppet will change
the configuration of HAproxy, the service won't restart.

- Set to false only: Service will never start even by Keepalived
- Set to false with tricking init script: Service will start once, only
  by Keealived but never restart after each config change
- Set to true: Service will be managed on all nodes, no ERROR, only
  warnings on BACKUP nodes, regarding binding.

For now, we switch to true and we plan to patch puppetlabs-haproxy to
improve it.

manifests/loadbalancer.pp

@@ -233,13 +233,7 @@ class cloud::loadbalancer(
   # Ensure Keepalived is started before HAproxy to avoid binding errors.
   class { 'keepalived': } ->
   class { 'haproxy':
-    service_manage => false
-  }
-  # Still allow HAproxy to start
-  if ($::osfamily == 'Debian') {
-    file { '/etc/default/haproxy':
-      content => 'ENABLED=1'
-    }
+    service_manage => true
   }
 
   keepalived::vrrp_script { 'haproxy':

spec/classes/cloud_loadbalancer_spec.rb

@@ -124,7 +124,7 @@ describe 'cloud::loadbalancer' do
         })
       end # configure vrrp_instance with BACKUP state
       it 'configure haproxy server without service managed' do
-        should contain_class('haproxy').with(:service_manage => false)
+        should contain_class('haproxy').with(:service_manage => true)
       end # configure haproxy server
     end # configure keepalived in backup
 
@@ -143,7 +143,7 @@ describe 'cloud::loadbalancer' do
         })
       end
       it 'configure haproxy server with service managed' do
-        should contain_class('haproxy').with(:service_manage => false)
+        should contain_class('haproxy').with(:service_manage => true)
       end # configure haproxy server
     end # configure keepalived in master