Not supported
**Describe the bug**
Starting from 0.5.16, I get a "device not supported" in homekit (the icon of the button is now a house!)

**Expected behavior**


**To Reproduce**
Steps to reproduce the behavior:
1. homebridge v 0.4.45
2. http-switch v 0.5.16
3. stateful switch with all three url (on, off, status) correctly configured

**Version** (output of `npm list -g homebridge homebridge-http-switch`)
 - homebridge: v 0.4.45
 - homebridge-http-switch:  v 0.5.16

**Configuration**
{
            "accessory": "HTTP-SWITCH",
            "switchType": "stateful",
            "name": "Specchio Bagno Max",
            "onUrl": "http://spbagnomax.maxhome/on",
            "offUrl": "http://spbagnomax.maxhome/off",
            "statusUrl": "http://spbagnomax.maxhome/status"
        },
        {
            "accessory": "HTTP-SWITCH",
            "switchType": "stateful",
            "name": "Specchio Bagno Fede",
            "onUrl": "http://spbagnofede.maxhome/on",
            "offUrl": "http://spbagnofede.maxhome/off",
            "statusUrl": "http://spbagnofede.maxhome/status"
        },

**Additional context**
Add any other context about the problem here.