Error on Stateful switch.
I am getting the following error in the logs when I set the switch to "stateful".  The switch works fine when set to "stateless" or "toggle".  It seems the plugin has a problem with a list of urlobjs when the switch is set to "stateful".  Homebridge, npm, node, and all plugins up to date.

Am I missing something or is this a bug?

Thanks for a great plugin.

![image](https://user-images.githubusercontent.com/3344008/146448868-0e3f79e9-d1eb-41a6-9edc-d762508bf3b2.png)

        {
            "accessory": "HTTP-SWITCH",
            "name": "Scenes Music Time",
            "switchType": "stateful",
            "multipleUrlExecutionStrategy": "series",
            "onUrl": [
                {
                    "method": "GET",
                    "url": "http://192.168.1.11/YamahaExtendedControl/v2/main/setPower?power=on"
                },
                {
                    "method": "GET",
                    "url": "http://192.168.1.12/YamahaExtendedControl/v2/main/setPower?power=on"
                },
                {
                    "method": "GET",
                    "url": "http://192.168.1.13/YamahaExtendedControl/v2/main/setPower?power=on"
                },
                {
                    "method": "GET",
                    "url": "http://192.168.1.14/YamahaExtendedControl/v2/main/setPower?power=on"
                },
                {
                    "method": "GET",
                    "url": "http://192.168.1.15/YamahaExtendedControl/v2/main/setPower?power=on"
                },
                {
                    "method": "GET",
                    "url": "http://192.168.1.16/YamahaExtendedControl/v2/main/setPower?power=on"
                }
            ],
            "offUrl": [
                {
                    "method": "GET",
                    "url": "http://192.168.1.11/YamahaExtendedControl/v2/main/setPower?power=standby"
                },
                {
                    "method": "GET",
                    "url": "http://192.168.1.12/YamahaExtendedControl/v2/main/setPower?power=standby"
                },
                {
                    "method": "GET",
                    "url": "http://192.168.1.13/YamahaExtendedControl/v2/main/setPower?power=standby"
                },
                {
                    "method": "GET",
                    "url": "http://192.168.1.14/YamahaExtendedControl/v2/main/setPower?power=standby"
                },
                {
                    "method": "GET",
                    "url": "http://192.168.1.15/YamahaExtendedControl/v2/main/setPower?power=standby"
                },
                {
                    "method": "GET",
                    "url": "http://192.168.1.16/YamahaExtendedControl/v2/main/setPower?power=standby"
                }
            ]
        },


