Rename 'dynamo' to 'storage backend' for logging

taar/recommenders/recommendation_manager.py

@@ -107,7 +107,7 @@ class RecommendationManager:
         client_info = self.profile_fetcher.get(client_id)
         if client_info is None:
             self.logger.info(
-                "Defaulting to empty results.  No client info fetched from dynamo."
+                "Defaulting to empty results.  No client info fetched from storage backend."
             )
             return []