Also clean users with avatars by default

Right now, we use in #set ($inactiveAuthorReferences = $services.antispam.getInactiveAuthors(30, false, $limit)) in AntiSpam.CleanInactiveUsers (false meaning to not clean users with avatars).

This was a protection set up initially when testing this new feature to avoid removing more users than expected. It's now proven to work well enough to change that option.