Fix MQTT binary switch

[dgomes]

Description:

I was getting this in my log files:

2018-11-12 00:21:26 WARNING (MainThread) [homeassistant.core] Unable to remove unknown listener <function async_track_point_in_utc_time.<locals>.point_in_time_listener at 0x102948378>

After some analysis I reached binary_sensor/mqtt line 157 where an async callback was supposed to be called in order to cancel an evt.async_call_later.

The proper fix would have been to await for self._delay_listener() but we are outside async function.

This patch fixes the warning, but I'm not sure if it is the right approach 😞

Related issue (if applicable): fixes #

Pull request in home-assistant.io with documentation (if applicable): home-assistant/home-assistant.io#<home-assistant.io PR number goes here>

Example entry for configuration.yaml (if applicable):

binary_sensor:
  - platform: mqtt
    state_topic: "test/1"
    payload_on: 1
    payload_off: 0
    name: test_mqtt_delay_off
    device_class: motion
    off_delay: 5

mosquitto_pub -h 192.168.1.100 -t test/1 -m 1 && mosquitto_pub -h 192.168.1.100 -t test/1 -m 0

Checklist:

• The code change is tested and works locally.
• Local tests pass with tox. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated in home-assistant.io

If the code communicates with devices, web services, or third-party tools:

• New dependencies have been added to the REQUIREMENTS variable (example).
• New dependencies are only imported inside functions that use them (example).
• New or updated dependencies have been added to requirements_all.txt by running script/gen_requirements_all.py.
• New files were added to .coveragerc.

If the code does not interact with devices:

• Tests have been added to verify that the new code works.

[amelchio]

That looks right, the await sounds wrong :)

[dgomes]

but setting the callback to None was part of the callback. 🤷‍♂️

It does work 😄 Tks!

[amelchio]

It sounds like you are mixing up self._delay_listener() and self.off_delay_listener(). The latter is not called when you manually call the former.