Refactor Contrail-API workers

Change-Id: I48a6512872f7cc5bad1ea9741e02070e2c2b1a78
diff --git a/README.rst b/README.rst
index e285e13..4baa550 100644
--- a/README.rst
+++ b/README.rst
@@ -921,7 +921,8 @@
     opencontrail:
       ...
       config:
-        api_workers: 3
+        api:
+          workers_count: 3
       ...
 
 Increase number of alarm-gen workers