added the localrc section to the local.conf

Change-Id: Iffcc61ca886df96e1dc7c0df3c02125cb2b4a7dc
diff --git a/doc/source/guides/multinode-lab.rst b/doc/source/guides/multinode-lab.rst
index a63260f..0b1ebb9 100644
--- a/doc/source/guides/multinode-lab.rst
+++ b/doc/source/guides/multinode-lab.rst
@@ -167,6 +167,7 @@
 
 ::
 
+    [[local|localrc]]
     HOST_IP=192.168.42.12 # change this per compute node
     FLAT_INTERFACE=eth0
     FIXED_RANGE=10.4.128.0/20