swh/production-cassandra: update storage config to use azure objstorage backend

swh/values/production-cassandra.yaml

@@ -198,13 +198,8 @@ storage:
       - cassandra08.internal.softwareheritage.org
     keySpace: swh
     consistencyLevel: LOCAL_QUORUM
-  objstorageClass: filtered
-  objstorageConfig:
-    storage_conf:
-      cls: remote
-      url: http://objstorage.internal.softwareheritage.org:5003/
-    filters_conf:
-    - type: readonly
+  objstorageClass: multiplexer
+  objstorageConfig: ${OBJSTORAGECONFIG}
 
 web:
   enabled: true