Don't initialize deploy_message again

Now the successful deployment prints

"Overcloud Deployed None"

It's already been initialized to 'without error' a few
lines earlier.

Change-Id: I915fb0701cb09c40a542cb66d9ac3b68bcc6e211

tripleoclient/v1/overcloud_deploy.py

@@ -970,7 +970,6 @@ class DeployOvercloud(command.Command):
         old_rcpath = None
         rcpath = None
         horizon_url = None
-        deploy_message = None
 
         try:
             # Force fetching of attributes