Reduce CPU browser load

VP8 code is not hardware accelerated. H.264 is, but needs to be configured https://github.com/jitsi/jitsi-meet/issues/2596#issuecomment-383915759

Parameters can be appended in URL like this

https://meet.jit.si/FooBar#config.resolution=360&config.constraints.video.height.ideal=360&config.constraints.video.height.max=360&config.preferH264=true&interfaceConfig.DISABLE_VIDEO_BACKGROUND=true

Check browser GPU support with about:support