better explanation here https://news.ycombinator.com/item?id=47106852
but in short they are changing whether string is empty, and query string "pending_delete" is same as "pending_delete=" and will return empty
Or, if they specified `/v1/prefixes?pending_delete=potato` it would return "correct" list of objects to delete
Or in other words "Go have types safety, fuck it, let's use strings like in '90s PHP apps instead"