Pass base url for binaries to cloud init

Related-Prod: PRODX-3456
Change-Id: Ia5856c09f6b9a558c27ba7da6334baffcddc0d7c
diff --git a/de/heat-templates/multirack.yaml b/de/heat-templates/multirack.yaml
index abcae03..321fabd 100644
--- a/de/heat-templates/multirack.yaml
+++ b/de/heat-templates/multirack.yaml
@@ -135,6 +135,9 @@
     type: string
     description: Default address pool for Docker ucp specific local networks
     default: '10.10.1.0/16'
+  binary_base_url:
+    type: string
+    default: 'http://binary.mirantis.com'
   tunnel_interface:
     type: string
     default: ''