[fix] fixes the nrm list command.

fixes a bug that was introduced in schema migration.

nrm/daemon.py

@@ -136,7 +136,7 @@ class Daemon(object):
             self.upstream_rpc_server.send(
                     client,
                     tag="list",
-                    payload=response)
+                    containers=response)
         else:
             logger.error("invalid command: %r", req.tag)