Library sync can't *remove* categories

[danieljohnson2]

You can add and remove categories to games in the Lutris client, and then sync, but the server copy only picks up added categories, and does not honor removals.

The behavior you get is that if you do remove a category and sync, the next sync after that will restore the category you removed.

I believe the offending code is in website/accounts/views.py around line 558. You can see this loop only ever adds; there's no removal.

A simple way to fix this might be just test if the new and old category lists match, and if not, clear the server list and copy in all the new categories. I optimistically assume the category lists will always be short!