Disable flow collection on collector side

Change-Id: I68bdfe75a2492d49644301731034b7405b07f33f
diff --git a/opencontrail/files/3.0/contrail-collector.conf b/opencontrail/files/3.0/contrail-collector.conf
index 4523cc1..5815552 100644
--- a/opencontrail/files/3.0/contrail-collector.conf
+++ b/opencontrail/files/3.0/contrail-collector.conf
@@ -28,6 +28,9 @@
 # Multiple IP:port are specified as single string separated by comma
 zookeeper_server_list={% for member in collector.database.members %}{{ member.host }}:2181{% if not loop.last %},{% endif %}{% endfor %}
 
+# Disable flow collection
+disable_flow_collection={{ collector.get('disable_flow_collection', 'false')|lower }}
+
 # dup=0
 hostip={{ collector.bind.address }} # Resolved IP of `hostname`
 # hostname= # Retrieved as `hostname`