Enable nova update_cells by default

PROD-36548

Change-Id: Ic1e431f639fa44b120b17f4f894f15cf5e377b7a
diff --git a/nova/control/cluster.yml b/nova/control/cluster.yml
index 30d759f..8adbb21 100644
--- a/nova/control/cluster.yml
+++ b/nova/control/cluster.yml
@@ -106,3 +106,4 @@
         protocol: ${_param:cluster_internal_protocol}
       metadata:
         password: ${_param:metadata_password}
+      update_cells: ${_param:nova_control_update_cells}