[Camera-ffmpeg] [FFMPEG] ffmpeg exited with code: 1 and signal: null (error)
Hi,

i installed your plugin but it will not show any Video. My config is:
```        {
            "cameras": [
                {
                    "name": "Name",
                    "videoConfig": {
                        "source": "-re -f mjpeg -i 'http://user:pass@172.29.1.100:8080/?action=stream'",
                        "stillImageSource": "-re -f mjpeg -i 'http://user:pass@172.29.1.100:8080/?action=capture'"
                    }
                }
            ],
            "platform": "Camera-ffmpeg"
        }
```
When i try to watch the video stream in Homeapp i can see in Homebridge log:
```
[6/26/2020, 4:43:40 PM] [Camera-ffmpeg] Snapshot from Flur at 1280:720
[6/26/2020, 4:43:41 PM] [Camera-ffmpeg] [FFMPEG] ffmpeg exited with code: 1 and signal: null (error)
```

Running `ffmpeg -re -f mjpeg -i 'http://User:pass@172.29.1.100:8080/?action=stream' out.mp` on the console of the Ubuntu Server records a nice video.

Whats wrong with my config?