ARGS:
MINIO_NOTIFY_MQTT_ENABLE*              (on|off)    enable notify_mqtt target, default is 'off'
MINIO_NOTIFY_MQTT_BROKER*              (uri)       MQTT server endpoint e.g. `tcp://localhost:1883`
MINIO_NOTIFY_MQTT_TOPIC*               (string)    name of the MQTT topic to publish
MINIO_NOTIFY_MQTT_USERNAME             (string)    MQTT username
MINIO_NOTIFY_MQTT_PASSWORD             (string)    MQTT password