I'm unable to get person or vehicle detection alerts.
**Describe The Problem:**
I'm unable to get person or vehicle detection alerts. I am able to get motion alerts.

**To Reproduce:**
I have added the following three features:
Enable.Motion.SmartDetect
Enable.Motion.SmartDetect.Person
Enable.Motion.SmartDetect.Vehicle

My understanding from the documentation is that `Enable.Motion.SmartDetect` is disabled by default, but adding theses, should enable it. (I do see the smart detection via the `Protect` UniFi app push notification).

**Logs:**
[30/08/2021, 09:58:49] [UniFi Protect] UDMPRO [UDM-PRO]: Connected to the Protect controller API (address: 192.168.1.1 mac: XXXXXXXXXX).
[30/08/2021, 09:58:49] [UniFi Protect] UDMPRO [UDM-PRO]: The user 'homebridge' requires the Administrator role in order to automatically configure camera RTSP streams.
[30/08/2021, 09:58:49] [UniFi Protect] UDMPRO [UDM-PRO]: Connected to the UniFi realtime update events API.
[30/08/2021, 09:58:49] [UniFi Protect] UDMPRO [UDM-PRO]: Discovered camera: Backyard [UVC G4 Pro] (address: 192.168.1.144 mac: XXXXXXXXXX).
[30/08/2021, 09:58:49] [UniFi Protect] UDMPRO [UDM-PRO]: Discovered camera: Front door [UVC G4 Doorbell] (address: 192.168.1.31 mac: XXXXXXXXXX).
[30/08/2021, 09:58:49] [UniFi Protect] UDMPRO [UDM-PRO]: Controller refresh interval set to 10 seconds.
[30/08/2021, 09:58:49] [UniFi Protect] UDMPRO [UDM-PRO] Backyard [UVC G4 Pro]: Smart motion detection enabled: person, vehicle.

**Environment:**

* **Homebridge Version:** 1.4.3
* **Node Version:** v14.17.4
* **Homebridge-UniFi-Protect Plugin Version:** homebridge-unifi-protect v4.4.2
* **UniFi Protect Version:** 1.19.0
* **UniFi Protect Controller Type:** UDMPro
* **UniFi Protect Controller Firmware Version:** 6.2.26
* **Apple Device and iOS / macOS / iPadOS / tvOS Version:** iOS 14 and macOS 10.16
* **Operating System and OS Version:** Raspbian

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