ju_ri URL is hard-coded because it's easier to work with multiple drivers. In case you use an external host like Amazon S3 for your images, then you usually don't need to change the links even if your forum changed domain.
There's no built-in solution for moving domains at the moment. One option like you did is to manually edit the database. Another would be to setup redirects from the old domain for the new domain, but that's more of a temporary solution if you planned to take all the files to the new host anyway.
