Specify JPA Database H2 in SpecificationBuilderTests (#2432)

Signed-off-by: Avgustin Marinov <Avgustin.Marinov@bosch.com>

hawkbit-repository/hawkbit-repository-jpa/src/test/java/org/eclipse/hawkbit/repository/jpa/rsql/sa/SpecificationBuilderTest.java

@@ -36,6 +36,7 @@ import org.springframework.orm.jpa.vendor.Database;
 
 @SuppressWarnings("java:S5961") // complex check because the matter is very complex
 @DataJpaTest(properties = {
+        "spring.jpa.database=H2",
         "logging.level.org.eclipse.hawkbit.repository.jpa.rsql=DEBUG"
 }, excludeAutoConfiguration = { FlywayAutoConfiguration.class })
 @EnableAutoConfiguration