users: don't log mod action for user deletions.

Don't log a mod action when a user deletes their own account. This isn't a moderator action, so it
doesn't belong here. Account deletions are still logged on the /user_events page (visible to mods only).

A mod action is still logged when the Owner-level user deletes someone else's account.

app/logical/user_deletion.rb

@@ -34,7 +34,7 @@ class UserDeletion
       rename
       reset_password
       async_delete_user
-      ModAction.log("deleted user ##{user.id}", :user_delete, subject: user, user: deleter)
+      ModAction.log("deleted user ##{user.id}", :user_delete, subject: user, user: deleter) if user != deleter
       UserEvent.create_from_request!(user, :user_deletion, request) if request.present?
       SessionLoader.new(request).logout(user) if user == deleter
     end