Error during setup of component mqtt (since version 0.48)

I have a problem for installation since version 0.48 ,0.49 … on my raspberry py 3 .

`2017-08-21 13:17:15 ERROR (MainThread) [homeassistant.setup] Error during setup of component mqtt Traceback (most recent call last):

File “/usr/local/lib/python3.4/dist-packages/homeassistant/setup.py”, line 191, in _async_setup_component result = yield from component.async_setup(hass, processed_config)

File “/usr/local/lib/python3.4/dist-packages/homeassistant/components/mqtt/init.py”, line 374, in async_setup will_message, birth_message, tls_version)

File “/usr/local/lib/python3.4/dist-packages/homeassistant/components/mqtt/init.py”, line 450, in init proto = mqtt.MQTTv311 AttributeError: ‘module’ object has no attribute ‘MQTTv311’`

Please how to correct this problem?

Thanks in advance !!!

nobody has had this problem (and corrected) ?