[TEST] only call TestCluster#afterTest() if cluster was successfully initialized

src/test/java/org/elasticsearch/test/ElasticsearchIntegrationTest.java

@@ -554,10 +554,13 @@ public abstract class ElasticsearchIntegrationTest extends ElasticsearchTestCase
                     initializeGlobalCluster(); // re-init that cluster
                 }
             }
+            if (currentCluster != null) {
+                // this can be null if the test fails due to static initialization ie. missing parameter on the cmd
                 currentCluster.afterTest();
                 currentCluster = null;
             }
         }
+    }
 
     public static TestCluster cluster() {
         return currentCluster;