HS100 not working on any update after v5.1.0
<!-- Provide a general summary in the Title above -->

### Expected Behavior
<!-- If you're describing a bug, tell us what should happen -->
HS100's work exceptionally fine on v5.1.0
<!-- If you're suggesting a change/improvement, tell us how it should work -->
Upgrading to later versions (as at 20/10/2020) cause device to not be able to be controlled by Homekit
### Current Behavior
<!-- If describing a bug, tell us what happens instead of the expected behavior -->
Upgrades to plug in broke ability to change status in Homekit, but still work if toggled by Homebridge 'Appliances' tab.
<!-- If suggesting a change/improvement, explain the difference from current behavior -->

### Steps to Reproduce (for bugs)
<!-- Please add a series of steps to reproduce the problem. -->
Upgrading breaks it
Downgrading to v5.1.0 fixes it.
### Versions
<!-- Please run commands and include versions below. -->
- **Node**:       `node --version` v12.18.3 
- **Homebridge**: `homebridge --
version` v1.3.0-beta.12
('upgraded to beta to  see if it fixed - it didn't)
- **OS**:         <!-- The version and architecture of your operating system --> MacOS 10.9.5

### Configuration
<!-- Please include the TplinkSmarthome platform section of your config.json file.
Paste between the the two ``` lines below.
-->
```json
        {
            "name": "TplinkSmarthome",
            "addCustomCharacteristics": true,
            "deviceTypes": [
                "plug",
                "bulb"
            ],
            "platform": "TplinkSmarthome"
        },
```

### Homebridge Log / Command Output
<!-- Paste relevant output between the two ``` lines below
  - Remove any sensitive information, passwords, etc.
  - If output is long:
    - Please extract only the relevant portions if possible (remove other plugin's output, etc)
    - Consider creating a gist, etc
  - However, please include the beginning of the log where the homebridge initialization happens if possible
-->
```
This line appears when broken:
[Tplink Smarthome] set Value: Invalid On: 0
```
