Add MQTT IP parm

Change-Id: I19ad078ede11f097b0536eedd0ea18f6f252f23d
diff --git a/person_detection/app.py b/person_detection/app.py
index 7652950..393b5d2 100644
--- a/person_detection/app.py
+++ b/person_detection/app.py
@@ -79,6 +79,9 @@
     args.add_argument("--num", default=config.NUMDEVICES,
                       help="Number of camera devices",
                       type=int)
+    args.add_argument("--mqttip", default=config.MQTTIP,
+                      help="IP address of MQTT",
+                      type=str)
     args.add_argument("--mbrlow", help="Low range of MBR", default=7000000,
                       type=int)
     args.add_argument("--mbrhigh", help="High range of MBR", default=10000000,