Multiple messages are being sent [Bug] 
**Describe the bug**
When I trigger an action for some reason this plugin publishes two messages to the MQTT broker. Sometimes this is fine but sometimes this causes automations to fire twice or weird things to show up in the home app. One of these weird things is when changing my radiator valve from HEAT to anything else it will get stuck in a weird loop where it will randomly publish messages and flick between states until you leave it alone for a bit and try again.

**Related devices**
Switches
Radiator Valves 

**To Reproduce**
1. Change the state of a device in the Home App
2. Look at the logs on Homebridge and you will see two publish messages
3. Look at the zigbee2mqtt logs on and you will see two or more messages being received an it responding for each message

**Expected behavior**
only one message to be sent for one action in the Home App

**MQTT messages**
[2/10/2021, 12:58:24] [zigbee2mqtt] Publish to 'zigbee2mqtt/xxxxx/set': '{"state_right":"OFF"}'
[2/10/2021, 12:58:26] [zigbee2mqtt] Publish to 'zigbee2mqtt/xxxxx/set': '{"state_right":"OFF"}'

**Versions used**
Please provide the version of the following pieces of software:
 - This plugin - 1.1.1
 - Homebridge - 1.2.5
 - Zigbee2MQTT (can be found in MQTT topic `zigbee2mqtt/bridge/info`) - 1.17.0
 - Homebridge Config UI X (if applicable) - 4.38.0
