Fix inconsistent Stacklight environment label

The previous version generated inconsistent labels between the
monitoring nodes and the other nodes. This change makes
stacklight_environment a mandatory parameter to avoid this problem.

https://github.com/Mirantis/mk-lab-salt-model/pull/209
diff --git a/heka/server.yml b/heka/server.yml
index 5141e40..f82cfc5 100644
--- a/heka/server.yml
+++ b/heka/server.yml
@@ -1,6 +1,4 @@
 parameters:
-  _param:
-    stacklight_environment: ${_param:cluster_domain}
   heka:
     server:
       extra_fields:
diff --git a/nagios/server/init.yml b/nagios/server/init.yml
index da4dcc4..49f4943 100644
--- a/nagios/server/init.yml
+++ b/nagios/server/init.yml
@@ -3,7 +3,6 @@
     nagios_notification_email: root@localhost
     nagios_host_dimension_key: nagios_host
     nagios_default_host_alarm_clusters: 00-clusters
-    stacklight_environment: ${_param:cluster_domain}
   nagios :
     server:
       enabled: true