Have io_reinit() reset run, lb number so execute obtains number of expected events.

Without this fix, CreateLumiBlockCollectionFromFile::io_reinit() removes all the seen lumi info, but fails to reset run and lb number (which may have been set on a previous execute()) so on the next execute() it doesn’t reset the number of expected events from the database, but sets them to 0 (CreateLumiBlockCollectionFromFile.cxx line 96, will actually implicit create an object). This behavior breaks MP-FAFE, where one event is processed on the mother before the workers are launched.