beta 5 doesn't seem to be passing "-vf" variable
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**Describe The Bug:**
<!-- A clear and concise description of what the bug is. -->
In the interface documentation, the 
However, when I manually set 1280x720 in config-ui-x, that information does not appear to be forced manually to ffmpeg.  

**To Reproduce:**
Use camera with resolution of 1920x1024, vf will not pass manual parameters as expected.

**Expected behavior:**
<!-- A clear and concise description of what you expected to happen. -->
"-vf" should pass the expected resolution manually set in the interface.
**Logs:**
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![Screen Shot 2020-07-18 at 2 42 11 PM](https://user-images.githubusercontent.com/5279205/87862449-04c10700-c905-11ea-939d-d80425f4b7b1.png)
```
[7/18/2020, 2:34:24 PM] [Camera-ffmpeg] Starting RIGHT Front Cam video stream (1920x1080, 20 fps, 800 kbps, 1316 mtu)... 
```
```
pi@dockerpi-c:~ $ pgrep -f -a ffmpeg
996 /usr/lib/node_modules/homebridge-camera-ffmpeg/node_modules/ffmpeg-for-homebridge/ffmpeg -rtsp_transport tcp -r 24 -i rtsp://root:XXXXXX@192.168.1.230:554/axis-media/media.amp?streamprofile=Media?tcp -map 0:0 -vcodec h264_omx -pix_fmt yuv420p -r 20 -f rawvideo -preset ultrafast -tune zerolatency -vf scale=1280:720 -b:v 299k -bufsize 598k -maxrate 299k -payload_type 99 -ssrc 12826153 -f rtp -srtp_out_suite AES_CM_128_HMAC_SHA1_80 -srtp_out_params YGRJjUBtp6oSOnWYXpDZ3qsqxr1nni4dGSiZNgp8 srtp://192.168.1.184:58694?rtcpport=58694&localrtcpport=58694&pkt_size=1316
25631 /usr/lib/node_modules/homebridge-camera-ffmpeg/node_modules/ffmpeg-for-homebridge/ffmpeg -rtsp_transport tcp -i rtsp://root:XXXXXX@192.168.1.233/axis-media/media.amp?streamprofile=Media?tcp&resolution=1280x720 -map 0:0 -vcodec libx264 -pix_fmt yuv420p -r 20 -f rawvideo -preset ultrafast -tune zerolatency -vf scale=1920:1080 -b:v 800k -bufsize 1600k -maxrate 800k -payload_type 99 -ssrc 3546742 -f rtp -srtp_out_suite AES_CM_128_HMAC_SHA1_80 -srtp_out_params CZNJ0I6PMoWO8UVHyGQl8fIagJsxcAdqK6z22jLr srtp://192.168.1.183:64518?rtcpport=64518&localrtcpport=64518&pkt_size=1316
```
```
Show the Homebridge logs here.
Remove any sensitive information.
```

**Homebridge Config:**

```json
Show your homebridge config.json here.
Remove any sensitive information, such as your homebridge-gsh / google-smarthome token.
```

**Screenshots:**
<!-- If applicable, add screenshots to help explain your problem. -->

**Environment:**

* **Node.js Version**: <!-- node -v -->
* **NPM Version**: <!-- npm -v -->
* **Homebridge Version**: <!-- homebridge -V -->
* **Homebridge Camera FFmpeg Version**:
* **Homebridge Config UI X Plugin Version**:
* **Operating System**: <!-- Raspbian / Ubuntu / Debian / Windows / macOS / Docker -->


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