[keyserver] Fix usersToUpdate logic in deleteAccount
Summary: Was looking at this when working on UPDATE_USER updates for updateUserAvatar and it looks like it wasn't actually excluding anything.
Test Plan:
Tested updated logic in updateUserSettings.
Before:
After:
(85999 is viewer.id)
Reviewers: ashoat, ginsu
Reviewed By: ashoat
Subscribers: tomek
Differential Revision: https://phab.comm.dev/D7677