Set metadata_password if not defined

To fix some broken models where this change wasn't reflected.

Change-Id: Ie75b6c60ce89601056f1004001290f6c00f233f9
diff --git a/nova/control/cluster.yml b/nova/control/cluster.yml
index 1bcc8b9..d47c5e1 100644
--- a/nova/control/cluster.yml
+++ b/nova/control/cluster.yml
@@ -10,6 +10,7 @@
     nova_cpu_allocation_ratio: 16.0
     nova_ram_allocation_ratio: 1.5
     nova_disk_allocation_ratio: 1.0
+    metadata_password: metadataPass
   nova:
     controller:
       enabled: true