Possibility of remove direct dependency to ffmpeg-for-homebridge
Hello,
I'm using openwrt and I have a problem with the ffmpeg-for-homebridge package on different platforms. I prefer to use the built-in ffmpeg. Would it be possible for homebridge-camera-ffmpeg not to have a direct dependency on this package, or at least if it doesn't find it, but the built-in ffmpeg will be available, then it won't fail?

Typically output without ffmpeg-for-homebridge:
```
Wed Sep  2 21:04:13 2020 daemon.err homebridge[2233]: [Wed Sep 02 2020 21:04:13 GMT+0000 (UTC)] ERROR LOADING PLUGIN homebridge-camera-ffmpeg:
Wed Sep  2 21:04:14 2020 daemon.err homebridge[2233]: [Wed Sep 02 2020 21:04:14 GMT+0000 (UTC)] Error: Cannot find module 'ffmpeg-for-homebridge'
Wed Sep  2 21:04:14 2020 daemon.err homebridge[2233]: Require stack:
Wed Sep  2 21:04:14 2020 daemon.err homebridge[2233]: - /usr/lib/node/homebridge-camera-ffmpeg/dist/streamingDelegate.js
Wed Sep  2 21:04:14 2020 daemon.err homebridge[2233]: - /usr/lib/node/homebridge-camera-ffmpeg/dist/index.js
Wed Sep  2 21:04:14 2020 daemon.err homebridge[2233]: - /usr/lib/node/homebridge/lib/plugin.js
Wed Sep  2 21:04:14 2020 daemon.err homebridge[2233]: - /usr/lib/node/homebridge/lib/pluginManager.js
Wed Sep  2 21:04:14 2020 daemon.err homebridge[2233]: - /usr/lib/node/homebridge/lib/api.js
Wed Sep  2 21:04:14 2020 daemon.err homebridge[2233]: - /usr/lib/node/homebridge/lib/server.js
Wed Sep  2 21:04:14 2020 daemon.err homebridge[2233]: - /usr/lib/node/homebridge/lib/cli.js
Wed Sep  2 21:04:14 2020 daemon.err homebridge[2233]: - /usr/lib/node/homebridge/bin/homebridge
Wed Sep  2 21:04:14 2020 daemon.err homebridge[2233]:     at Function.Module._resolveFilename (internal/modules/cjs/loader.js:965:15)
Wed Sep  2 21:04:14 2020 daemon.err homebridge[2233]:     at Function.Module._load (internal/modules/cjs/loader.js:841:27)
Wed Sep  2 21:04:14 2020 daemon.err homebridge[2233]:     at Module.require (internal/modules/cjs/loader.js:1025:19)
Wed Sep  2 21:04:14 2020 daemon.err homebridge[2233]:     at require (internal/modules/cjs/helpers.js:72:18)
Wed Sep  2 21:04:14 2020 daemon.err homebridge[2233]:     at Object.<anonymous> (/usr/lib/node/homebridge-camera-ffmpeg/src/streamingDelegate.ts:30:22)
Wed Sep  2 21:04:14 2020 daemon.err homebridge[2233]:     at Module._compile (internal/modules/cjs/loader.js:1137:30)
Wed Sep  2 21:04:14 2020 daemon.err homebridge[2233]:     at Object.Module._extensions..js (internal/modules/cjs/loader.js:1157:10)
Wed Sep  2 21:04:14 2020 daemon.err homebridge[2233]:     at Module.load (internal/modules/cjs/loader.js:985:32)
Wed Sep  2 21:04:14 2020 daemon.err homebridge[2233]:     at Function.Module._load (internal/modules/cjs/loader.js:878:14)
Wed Sep  2 21:04:14 2020 daemon.err homebridge[2233]:     at Module.require (internal/modules/cjs/loader.js:1025:19)
```

If I remove **pathToFfmpeg** constant from streamingDelegate.js it works fine.

Is it possible to make a better solution?


Thank you,
Zbynek Kocur