LK

Results 2 issues of LK

![image](https://user-images.githubusercontent.com/25656788/191077731-b197e13c-012e-4cbe-8ac8-060367526954.png)

建议在此行后面 https://github.com/MinatoAquaCrews/nonebot_plugin_fortune/blob/c7846f756ed01fd7e4f4f9474fe35f600590dd04/nonebot_plugin_fortune/utils.py#L54 后面加上 `img = img.convert("RGB") ` 以免报错