Fix test with dirty class assertion

Signed-off-by: Maciej Lisowski <[email protected]>

extensions/narayana-jta/deployment/src/test/java/io/quarkus/narayana/quarkus/TransactionJdbcObjectStoreValidationFailureTest.java

@@ -24,7 +24,7 @@ public class TransactionJdbcObjectStoreValidationFailureTest {
             .setForcedDependencies(List.of(Dependency.of("io.quarkus", "quarkus-jdbc-h2", Version.getVersion())))
             .assertException(t -> {
                 Throwable rootCause = ExceptionUtil.getRootCause(t);
-                if (rootCause instanceof ConfigurationException) {
+                if (rootCause.getClass().getName().equals(ConfigurationException.class.getName())) {
                     assertTrue(rootCause.getMessage().contains(
                             "The Narayana JTA extension is configured to use the datasource 'test' but that datasource is not configured."));
                 } else {