api: connect to CCUJACK MQTT broker on startup

api/src/dooris_api/__init__.py

@@ -52,6 +52,12 @@ def main():
         default=os.environ.get("DOORIS_CCUJACK_URL", "https://hmdooris-ccu.ccchh.net:2122"),
         help="The URL under which a CCUJACK instance is hosted that actually operates the locks",
     )
+    argp.add_argument(
+        "--ccujack-mqtt",
+        required=False,
+        default=os.environ.get("DOORIS_CCUJACK_MQTT", "hmdooris-ccu.ccchh.net:1883"),
+        help="The $HOSTNAME:$PORT of the CCUJack embedded MQTT server",
+    )
     argp.add_argument(
         "--ccujack-user",
         required="DOORIS_CCUJACK_USER" not in os.environ,