Fix availability_zone indentation

Related-Prod: PRODX-19754
Change-Id: I3fc02aeba1b98c8829834f3636fd2872f1963715
diff --git a/de/heat-templates/fragments/SrvInstancesVMCeph.yaml b/de/heat-templates/fragments/SrvInstancesVMCeph.yaml
index b3db55e..17b2593 100644
--- a/de/heat-templates/fragments/SrvInstancesVMCeph.yaml
+++ b/de/heat-templates/fragments/SrvInstancesVMCeph.yaml
@@ -81,7 +81,7 @@
       # Don't mount ephemeral0 to /mnt as it's by default
       mounts:
         - [ ephemeral0, null ]
-   availability_zone:
+  availability_zone:
     type: string
     default: nova