Play Framework

When [Hibernate Envers](https://hibernate.org/orm/envers/) is triggered via an `@Audited` annotation, it attempts to insert a record in a related `AUD` table. However, Play! assumes all related entities extend `JPABase`, which the `AUD` tables don't. This leads to a `ClassCastException` because `HashMap` is cast to `JPABase`. By adding a check for `JPABase` here, we can avoid this problem. This effectively also checks for 'not null' which the previous implementation did.