Fix Heka meta for OpenContrail deployments

Change-Id: I2b5226acd8496a71fe25ca9cd67e6a488da8b8d3
diff --git a/neutron/meta/heka.yml b/neutron/meta/heka.yml
index 422ff50..17fdc06 100644
--- a/neutron/meta/heka.yml
+++ b/neutron/meta/heka.yml
@@ -223,6 +223,7 @@
         service: neutron-data
         nagios_host: 01-service-clusters
     {%- endfor %}
+{%- if neutron_agents|length > 0 %}
     neutron_data:
       policy: highest_severity
       alerting: enabled_with_notification
@@ -235,4 +236,4 @@
       dimension:
         cluster_name: neutron-data
         nagios_host: 00-top-clusters
-
+{%- endif %}