Remove norelease

Issue elastic/x-pack-elasticsearch#820 filed to track progress of better error handling, but not a blocker so removing
the norelease

Original commit: elastic/x-pack-elasticsearch@82cf6eebe2

plugin/src/main/java/org/elasticsearch/xpack/ml/job/persistence/JobStorageDeletionTask.java

@@ -103,7 +103,6 @@ public class JobStorageDeletionTask extends Task {
 
         // Step 2. DBQ done, delete the state
         // -------
-        // TODO norelease more robust handling of failures?
         ActionListener<BulkByScrollResponse> dbqHandler = ActionListener.wrap(bulkByScrollResponse -> {
                     if (bulkByScrollResponse.isTimedOut()) {
                         logger.warn("DeleteByQuery for indices [" + indexName + ", " + indexPattern + "] timed out.");