Start WPS does not work
Hello!
The WPS switch does not start the WPS process on my FritzBox 7590 AX.

When I tap on the WPS switch, I see in the logs:
`[26.09.2021, 17:02:50] [FritzPlatform] FritzBox 7590-AX Wps (wps): ON`
But after the next refresh, a few seconds later the WPS switch sets back to OFF.

My config is:
 ```
{
            "platform": "FritzPlatform",
            "name": "FritzPlatform",
            "debug": false,
            "devices": [
                {
                    "active": true,
                    "name": "FritzBox 7590-AX",
                    "host": "xxxxx",
                    "port": 49000,
                    "username": "xxxxxxx",
                    "password": "xxxxxxx",
                    "ssl": true,
                    "tr064": true,
                    "igd": false,
                    "manufacturer": "Fritz Box",
                    "model": "7590-AX",
                    "serialNumber": "12345",
                    "master": true,
                    "readOnly": false,
                    "hide": true,
                    "connection": "cable",
                    "options": {
                        "wifi_guest": "switch",
                        "wifi_5ghz": "switch",
                        "wifi_2ghz": "switch",
                        "wps": "switch",
                        "led": "switch"
                    }
                },
                {
                    "active": true,
                    "name": "FritzRepeater 6000",
                    "host": "xxxxxxx",
                    "port": 49000,
                    "username": "xxxxxxxxx",
                    "password": "xxxxxxxxxx",
                    "ssl": true,
                    "tr064": true,
                    "igd": false,
                    "manufacturer": "Fritz Box",
                    "model": "Repeater",
                    "serialNumber": "123456",
                    "readOnly": false,
                    "oldFW": false,
                    "connection": "repeater",
                    "hide": true,
                    "wifiUnits": 3,
                    "options": {
                        "wifi_guest": "switch",
                        "wifi_5ghz": "switch",
                        "wifi_2ghz": "switch",
                        "wps": "switch",
                        "led": "switch"
                    }
                }
            ],
            "callmonitor": {
                "port": 1012
            },
            "options": {
                "polling": {
                    "timer": 10
                }
            },
            "extras": {
                "dnsServer": {
                    "active": true,
                    "preferredDns": "185.37.37.37",
                    "alternateDns": "185.37.39.39",
                    "accType": "switch"
                }
            }
        },
```

I have latest Homebridge 1.32.4 and plugin 6.0.16.

Maybe something wrong in my config to have this work with new FritzBox model 7590 AX?
Guest switch is working great though!