What was the mini-patch update for?

League bugged out and froze (like it usually does every time I'm in League and a patch comes out). So I exit out, re-open, and it starts going through the normal process of downloading a patch and making me agree once it's finished. But I see no notes or anything different, and the main branch of the version is still 6.20 (meaning it's a sub-patch). Is it just bug fixes and stuff?