v1.1.9: An error occured while testing the downloaded ffmpeg binary
I'm using a custom compiled ffmpeg version (as oppose to apt binary package). When installing the last version of homebridge-nest-cam2 (1.1.9) I get the following error:

```
~/.npm# npm -g update homebridge-nest-cam2 --unsafe-perm

> ffmpeg-for-homebridge@0.0.3 install /usr/lib/node_modules/homebridge-nest-cam2/node_modules/ffmpeg-for-homebridge
> node install.js

Downloading ffmpeg from https://github.com/homebridge/ffmpeg-for-homebridge/releases/latest/download/ffmpeg-debian-x86_64.tar.gz
100% - Download Complete
/root/.npm/_ffmpeg_for_homebridge/ffmpeg: error while loading shared libraries: libmvec.so.1: cannot open shared object file: No such file or directory
An error occured while testing the downloaded ffmpeg binary.
+ homebridge-nest-cam2@1.1.9
added 16 packages from 6 contributors and updated 1 package in 4.231s
```

Apparently it is trying to install another binary and it is missing some dependency.