Update database query after schema changes

The Wiki Replicas have had schema changes:

• *_user and *_user_text fields were dropped.
• there is a new 'actor' table

See https://wikitech.wikimedia.org/wiki/News/Actor_storage_changes_on_the_Wiki_Replicas

Here, we retrieve the actor id from old_image and image,
do an additional join on the actor table to get the user_id,
which we need in order to get the user_registration.

Bug: T224862