[Bug]: Disarming Dufy Security Fails and Crashes Homebridge Server
### What happened?

When Eufy Security is switched from any status to disarmed/off from HomeKit, it fails and throws the below error. Also causes the HomeBridge server to crash and reboot. This issue did not exist prior to the 2.0 update. 

Want to note that I love this plugin and am reporting this issue to help the community.



### Device Type

Station (Supported)

### Plugin Version

v2.0.x (Supported)

### HomeBridge Version

v1.4.x (Supported)

### NodeJS Version

v16 (Supported)

### Operating System

Mac OS X 11+ (Supported)

### Relevant log output

```shell
[5/29/2022, 10:33:06 PM] InvalidPropertyValueError: Value "NaN" isn't a valid value for property "guardMode"
    at validValue (/usr/local/lib/node_modules/homebridge-eufy-security/node_modules/eufy-security-client/src/utils.ts:114:19)
    at Station.setGuardMode (/usr/local/lib/node_modules/homebridge-eufy-security/node_modules/eufy-security-client/src/http/station.ts:484:19)
    at StationAccessory.handleSecuritySystemTargetStateSet (/usr/local/lib/node_modules/homebridge-eufy-security/src/accessories/StationAccessory.ts:212:24)
    at SecuritySystemTargetState.<anonymous> (/usr/local/lib/node_modules/homebridge/node_modules/hap-nodejs/src/lib/Characteristic.ts:1676:42)
    at step (/usr/local/lib/node_modules/homebridge/node_modules/tslib/tslib.js:144:27)
    at Object.next (/usr/local/lib/node_modules/homebridge/node_modules/tslib/tslib.js:125:57)
    at /usr/local/lib/node_modules/homebridge/node_modules/tslib/tslib.js:118:75
    at new Promise (<anonymous>)
    at __awaiter (/usr/local/lib/node_modules/homebridge/node_modules/tslib/tslib.js:114:16)
    at SecuritySystemTargetState.Characteristic.handleSetRequest (/usr/local/lib/node_modules/homebridge/node_modules/hap-nodejs/dist/lib/Characteristic.js:824:38)
    at Bridge.<anonymous> (/usr/local/lib/node_modules/homebridge/node_modules/hap-nodejs/src/lib/Accessory.ts:1810:29)
    at step (/usr/local/lib/node_modules/homebridge/node_modules/tslib/tslib.js:144:27)
    at Object.next (/usr/local/lib/node_modules/homebridge/node_modules/tslib/tslib.js:125:57)
    at /usr/local/lib/node_modules/homebridge/node_modules/tslib/tslib.js:118:75
    at new Promise (<anonymous>)
    at __awaiter (/usr/local/lib/node_modules/homebridge/node_modules/tslib/tslib.js:114:16)
[5/29/2022, 10:33:06 PM] Got SIGTERM, shutting down Homebridge...
[5/29/2022, 10:33:06 PM] [Harmony Hub Living Room] INFO - shutdown
[5/29/2022, 10:33:06 PM] [EufySecurity-2.0.0] WARN:  Push Closed!
[5/29/2022, 10:33:06 PM] [EufySecurity-2.0.0] INFO:  Finished shutdown!
```
