Problem with `ingest_publication`

[kelle]

There's a logic error somewhere.

Calling:
ingest_publication(db, doi="10.1088/2041-8205/777/2/L20", ignore_ads=True)
yields:

line 408, in ingest_publication
   logger.debug(f"Adding {new_ref} to Publications table using {using}")
                                                                ^^^^^
UnboundLocalError: cannot access local variable 'using' where it is not associated with a value