More reliable uploading + cool error page (Pixiv Fanbox)

Hi all, if you were having issues uploading files or were seeing 504 error, this can often happen with large uploads because I hadn't setup the web server properly. I have now fixed this, any single file that takes less than an hour to upload should now work!

Additionally, there was an error with the databse yesterday that I was able to fully fix in less than half a day, suprise.

Lastly, I made a new custom error page for when the server goes down and you see "error 504" on the web. Check it out: https://cloud.cutefunny.moe/error/502.html