Remove S3 credentials from debug log

While sorting image locations using store weight, glance logs a
debug message which logs secret and access key for s3 backend.

Removing the debug log to avoid leaking of the s3 credentials.

Closes-Bug: #2095304
SecurityImpact

Change-Id: I24073c1b1e5ea92357d9a774e6c9c9cbf0980a44
(cherry picked from commit 33fa9596eb)
(cherry picked from commit d1cc917a29)

glance/common/utils.py

@@ -733,5 +733,9 @@ def sort_image_locations(locations):
         return store.weight if store is not None else 0
 
     sorted_locations = sorted(locations, key=get_store_weight, reverse=True)
-    LOG.debug(('Sorted locations: %s'), sorted_locations)
+    scrubbed = []
+    for loc in sorted_locations:
+        scrubbed.append({'store_name': loc["metadata"].get("store")})
+
+    LOG.debug(('Sorted locations: %s'), scrubbed)
     return sorted_locations