BibHarvest: more gentle speed test

• Increases to 0.03 seconds the expectation in the corresponding regression tests for the maximum average amount of time to return a record in oai_dc via the OAI-PMH protocol. The previous value, 0.02 was right over the current time range, when running regression tests in a slow virtual machine with low quantity of RAM, especially since oai_dc formatting of records is now fully integrated in BibFormat.