FIX: use isEqualTo - because DB2 driver does not use Integer.valueOf

ebean-test/src/test/java/io/ebeaninternal/server/core/DefaultServer_getReferenceTest.java

@@ -41,7 +41,7 @@ public class DefaultServer_getReferenceTest extends BaseTestCase {
     Vehicle reference = DB.reference(Vehicle.class, car.getId());
 
     assertThat(reference).isInstanceOf(Car.class);
-    assertThat(reference.getId()).isSameAs(car.getId());
+    assertThat(reference.getId()).isEqualTo(car.getId());
 
     DB.delete(car);
   }