Don't start thread before Task.run()

[kenoss]

Code like

    cap = NVArgusCameraCapture((CAPTURE_WIDTH, CAPTURE_HEIGHT), FPS)
    app.register_task(cap)

    # Classifier task
    conv = Classifier((CAPTURE_WIDTH, CAPTURE_HEIGHT)) 
    app.register_task(conv)    

    # Presenter task
    pres = Presenter(settings, cmd)
    app.register_task(pres)

    # Make task connection
    cap.connect(conv) # from `cap` to `conv`
    conv.connect(pres)  # from `conv` to `pres`

    # Start application
    app.run()

should reproduce the following error:

Traceback (most recent call last):
  File "/usr/local/lib/python3.6/dist-packages/actfw_jetson/camera.py", line 97, in _appsink_on_new_sample
    slf._outlet(frame)
  File "/usr/local/lib/python3.6/dist-packages/actfw_core/task/producer.py", line 40, in _outlet
    self.out_queues[self.out_queue_id].put(o, timeout=1)
IndexError: list index out of range

I guess this is because NVArgusCameraCapture.__init__() starts thread. Task must produce data after app.run() (More preceicely, after Task.connect()).
This code should be sit in NVArgusCameraCapture.run().