No cameras detected
**Describe The Problem:**
I've just installed this plugin and can't see any errors in the logs. The issue is that I can't see any accessories (cameras/doorbell) and can't see any topics on MQTT created by this plugin.

**Logs:**
```
homebridge    | [1/5/2021, 5:44:45 PM] Loaded plugin: homebridge-unifi-protect@4.3.5
homebridge    | [1/5/2021, 5:44:45 PM] Registering platform 'homebridge-unifi-protect.UniFi Protect'
.....
homebridge    | [1/5/2021, 5:44:45 PM] [UniFi Protect] Initializing UniFi Protect platform...
```

**Homebridge Configuration:**

```
    "platforms": [
        {
            "name": "Config",
            "port": 8888,
            "platform": "config"
        },
        {
            "controllers": [
                {
                    "address": "192.168.1.7",
                    "doorbellMessages": [
                        {
                            "duration": 60,
                            "message": "Test"
                        },
                        {
                            "duration": 60,
                            "message": "test2"
                        }
                    ],
                    "mqttTopic": "unifi/protect",
                    "mqttUrl": "mqtt://192.168.1.102:1884",
                    "password": "xxxxx",
                    "username": "xxxxx"
                }
            ],
            "platform": "UniFi Protect"
        }
    ]
```

**Environment:**

* **Homebridge Version:** v1.2.5
* **Node Version:** v14.15.3
* **Homebridge-UniFi-Protect Plugin Version:**
* **UniFi Protect Version:** Controller 1.13.7
* **UniFi Protect Controller Type:** UCKgen2+
* **UniFi Protect Controller Firmware Version:**v.1.1.0
* **Operating System and OS Version:** Docker 

