Error in Log (Found left-over)
**Describe The Bug:**
I have a lot of errors in my Log.

**To Reproduce:**
After Restart

```
homebridge.service: Found left-over process 1153 (ffmpeg) in control group while starting unit. Ignoring.
This usually indicates unclean termination of a previous run, or service implementation deficiencies.
homebridge.service: Found left-over process 1401 (ffmpeg) in control group while starting unit. Ignoring.
This usually indicates unclean termination of a previous run, or service implementation deficiencies.
homebridge.service: Found left-over process 11469 (ffmpeg) in control group while starting unit. Ignoring.
This usually indicates unclean termination of a previous run, or service implementation deficiencies.
homebridge.service: Found left-over process 11679 (ffmpeg) in control group while starting unit. Ignoring.
This usually indicates unclean termination of a previous run, or service implementation deficiencies.
homebridge.service: Found left-over process 11707 (ffmpeg) in control group while starting unit. Ignoring.
This usually indicates unclean termination of a previous run, or service implementation deficiencies.
homebridge.service: Found left-over process 12013 (ffmpeg) in control group while starting unit. Ignoring.
This usually indicates unclean termination of a previous run, or service implementation deficiencies.
homebridge.service: Found left-over process 25976 (ffmpeg) in control group while starting unit. Ignoring.
This usually indicates unclean termination of a previous run, or service implementation deficiencies.
homebridge.service: Found left-over process 4613 (ffmpeg) in control group while starting unit. Ignoring.
```

**Homebridge Config:**

```json
{
            "platform": "Camera-ffmpeg",
            "name": "Cameras",
            "cameras": [
                {
                    "name": "Haustür",
                    "manufacturer": "Unitoptek",
                    "model": "ABC-123",
                    "serialNumber": "1234567890",
                    "firmwareRevision": "1.0",
                    "motion": true,
                    "porthttp": 51824,
                    "motionTimeout": 1,
                    "doorbell": true,
                    "doorbellSwitch": true,
                    "switches": true,
                    "videoConfig": {
                        "source": "-rtsp_transport tcp -re -i rtsp://admin:XXX@192.168.0.42:554/11",
                        "stillImageSource": "-i http://admin:XXX@192.168.0.42/web/tmpfs/snap.jpg",
                        "additionalCommandline": "-x264-params intra-refresh=1:bframes=0",
                        "maxStreams": 2,
                        "maxWidth": 1280,
                        "maxHeight": 720,
                        "maxFPS": 15,
                        "vcodec": "copy",
                        "audio": true,
                        "debug": false
                    }
```

**Environment:**

* **Node.js Version**:
v12.18.1
* **NPM Version**: 
v6.14.5
* **Homebridge Version**: 
1.1.1
* **Homebridge Camera FFmpeg Version**:
2.3.2
* **Homebridge Config UI X Plugin Version**:
4.23.2
* **Operating System**: 
Raspberry

