Fix nuxeo-lts build failing on TestAuditStorage

The nuxeo-lts build is failing since May the 21st on this test class: TestAuditStorage.

From investigation, it seems that hibernate doesn't fully flush/reload/something between tests and the following scenario happens:

• previous tests create more than 1 000 entries
• created entries are deleted before TestAuditStorage run
• TestAuditStorage tries to create 56 entries with ids starting from 1001
• all entries from 1001 to x won't be effectively created in the DB, where x is the latest entry id created from previous test