Add filter "user_id" for receiver list

This patch revises the help message of receiver list, to add the
filter "user_id".

Depends-On: Ic4c23e0216551a3707b49b9f8868c9aa41d76281,
            I096291a2860125681faee80d31be48f585996e7c,
            Ia33a0df2909ba93a66ac61f3b729671933aae9fa
Change-Id: Ief2a928cec82f9a0adf1be7a4fcbecd0220ae17f
Partial-Bug: #1653613
(cherry picked from commit 1c4ddad806)

senlinclient/v1/receiver.py

@@ -37,7 +37,8 @@ class ListReceiver(command.Lister):
             help=_("Filter parameters to apply on returned receivers. "
                    "This can be specified multiple times, or once with "
                    "parameters separated by a semicolon. The valid filter "
-                   "keys are: ['name', 'type', 'action', 'cluster_id']"),
+                   "keys are: ['name', 'type', 'action', 'cluster_id', "
+                   "'user_id']"),
             action='append'
         )
         parser.add_argument(