Fallback poster

This video uses fallback for poster. It can take a while for YouTube to respond when a requested poster is missing. This is what causes the delay.

What you're seeing here is the basically the worst case scenario because we request `maxres` WebP poster for an old video that doesn't have WebP at all and only has `hqdefault.jpg`.

1. `maxresdefault.webp` is missing -> swtich to `sddefault.webp`
2. `sddefault.webp` is missing -> switch to `hqdefault.webp`
3. `hqdefault.webp` is missing -> switch to `hqdefault.jpg`
4. `hqdefault.jpg` exists

var LiteYTEmbedConfig = {
    useFallback: true
};