Child bridge crashing since upgrade: TypeError: Cannot read properties of null (reading 'temperature')
**Describe The Problem:**
After upgrading the Unifi-Protect plugin to v6.0.1, the child bridge keeps crashing/restarting

**To Reproduce:**
No steps really, I just upgraded and started experiencing the error. Restarting homebridge does not help.

**Logs:**
<!-- In order to be helpful, include the relevant logs from Homebridge, if applicable. -->

```
[27/03/2023, 16:52:15] [homebridge-unifi-protect] Launched child bridge with PID 8568
[27/03/2023, 16:52:16] Registering platform 'homebridge-unifi-protect.UniFi Protect'
[27/03/2023, 16:52:16] [homebridge-unifi-protect] Loaded homebridge-unifi-protect v6.0.1 child bridge successfully
[27/03/2023, 16:52:16] Loaded 11 cached accessories from cachedAccessories.0EF8354E1149.
[27/03/2023, 16:52:17] Homebridge v1.6.0 (HAP v0.11.0) (homebridge-unifi-protect) is running on port 44494.
[27/03/2023, 16:52:17] [homebridge-unifi-protect] Connected to the UniFi Protect API at a.b.c.d.
TypeError: Cannot read properties of null (reading 'temperature')
    at ProtectNvrSystemInfo.getCpuTemp (file:///usr/local/lib/node_modules/homebridge-unifi-protect/src/protect-nvr-systeminfo.ts:209:47)
    at ProtectNvrSystemInfo.configureTemperatureSensor (file:///usr/local/lib/node_modules/homebridge-unifi-protect/src/protect-nvr-systeminfo.ts:201:94)
    at ProtectNvrSystemInfo.updateDevice (file:///usr/local/lib/node_modules/homebridge-unifi-protect/src/protect-nvr-systeminfo.ts:141:13)
    at ProtectNvrSystemInfo.configureAccessory (file:///usr/local/lib/node_modules/homebridge-unifi-protect/src/protect-nvr-systeminfo.ts:102:33)
    at new ProtectNvrSystemInfo (file:///usr/local/lib/node_modules/homebridge-unifi-protect/src/protect-nvr-systeminfo.ts:28:10)
    at ProtectNvr.ufpStartupHandler (file:///usr/local/lib/node_modules/homebridge-unifi-protect/src/protect-nvr.ts:184:23)
    at Object.onceWrapper (node:events:628:26)
    at ProtectApi.emit (node:events:513:28)
    at ProtectApi.bootstrapController (file:///usr/local/lib/node_modules/homebridge-unifi-protect/node_modules/unifi-protect/src/protect-api.ts:256:10)
    at processTicksAndRejections (node:internal/process/task_queues:95:5)
[27/03/2023, 16:52:18] [homebridge-unifi-protect] Child bridge process ended
[27/03/2023, 16:52:18] [homebridge-unifi-protect] Process Ended. Code: 1, Signal: null
[27/03/2023, 16:52:25] [homebridge-unifi-protect] Restarting Process...

[27/03/2023, 16:52:26] [homebridge-unifi-protect] Launched child bridge with PID 8579
[27/03/2023, 16:52:26] Registering platform 'homebridge-unifi-protect.UniFi Protect'
[27/03/2023, 16:52:26] [homebridge-unifi-protect] Loaded homebridge-unifi-protect v6.0.1 child bridge successfully
```

**Homebridge Configuration:**

```json
        {
            "name": "Config",
            "port": 8581,
            "auth": "form",
            "theme": "auto",
            "tempUnits": "f",
            "lang": "auto",
            "platform": "config"
        },
        {
            "controllers": [
                {
                    "address": "removed",
                    "password": "removed",
                    "username": "removed"
                }
            ],
            "options": [
                "Enable.Nvr.SystemInfo"
            ],
            "_bridge": {
                "username": "removed",
                "port": 44494
            },
            "platform": "UniFi Protect"
        },
```

**Screenshots:**
N/A

**Environment:**

* **Homebridge Version:** <!-- homebridge -V --> 1.6.0
* **Node Version:** <!-- node -v --> v18.14.2
* **Homebridge-UniFi-Protect Plugin Version:** 6.0.1
* **UniFi Protect Version:** <!-- Read the Protect version line from https://unifi-controller/protect/settings --> 2.2.11
* **UniFi Protect Controller Type:** <!-- UCKgen2+, UDMP, UNVR, etc. --> UCKgen2
* **UniFi Protect Controller Firmware Version:** <!-- Read the firmware line from https://unifi-controller/settings/general --> 2.4.8
* **Apple Device and iOS / macOS / iPadOS / tvOS Version:**<!-- Type of Apple device you're using and associated OS version --> N/A
* **Operating System and OS Version:** <!-- Raspbian / Ubuntu / Debian / Windows / macOS / Docker --> Debian 10.11

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