Remove debug stuff that should not be there

swh/export/journalprocessor.py

@@ -562,8 +562,6 @@ class JournalProcessorWorker:
         It uses an on-disk set to make sure that each object is only ever
         processed once.
         """
-        if obj is None:
-            return
         if getattr(obj, "author", None) is not None:
             self._add_person(obj.author)
         if getattr(obj, "committer", None) is not None: