Set contrail-api workers count to 1 by default

Change-Id: If65b0318ae305dc34c861d828f6e063a639e58ec
Related-PROD: PROD-27001
(cherry picked from commit 31d4becfa98c11bbdb77d0c6c9e3d8f95e479d77)
diff --git a/opencontrail/control/cluster4_0.yml b/opencontrail/control/cluster4_0.yml
index 95b0d90..12a344e 100644
--- a/opencontrail/control/cluster4_0.yml
+++ b/opencontrail/control/cluster4_0.yml
@@ -27,7 +27,7 @@
     opencontrail_controller_container_name: opencontrail_controller_1
     opencontrail_analytics_container_name: opencontrail_analytics_1
     opencontrail_analyticsdb_container_name: opencontrail_analyticsdb_1
-    opencontrail_api_workers_count: 6
+    opencontrail_api_workers_count: 1
     analytics_vip_address: ${_param:opencontrail_analytics_address}
 # Temprorary fix for MOS9 packages to pin old version of kafka
   linux: