After removing ~/.cache/anime-game-launcher, no background image at first startup

[CHN-beta]

After removing ~/.cache/anime-game-launcher, the first time launch anime-game-launcher will get an error "failed to download background image, no such file or dictionary". The second time launch works fine.

Steps to reproduce:

1. Set classical style in settings. Save settings and close anime-game-launcher.
2. Remove ~/.cache/anime-game-launcher.
3. Launch anime-game-launcher, and it gets the error, leaving only a transparent background.

Removing cache files such as ~/.cache on reboot is common on some distributions such as NixOS (to make things reproducible). I think the directory should be created before try to download background image.