Set executor of CompletableFuture for response with no content. (heli…

…don-io#4540)

* Set executor of CompletableFuture for response with no content.

* Fix copyright year

* Fix checkstyle

jersey/connector/src/main/java/io/helidon/jersey/connector/HelidonConnector.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, 2021 Oracle and/or its affiliates.
+ * Copyright (c) 2020, 2022 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -204,7 +204,8 @@ public String getReasonPhrase() {
 
         final CompletionStage<InputStream> stream = HelidonStructures.hasEntity(webClientResponse)
                 ? webClientResponse.content().as(InputStream.class)
-                : CompletableFuture.supplyAsync(() -> NO_CONTENT_INPUT_STREAM);
+                : CompletableFuture.supplyAsync(() -> NO_CONTENT_INPUT_STREAM,
+                                                executorServiceKeeper.getExecutorService(requestContext));
 
         return stream.thenApply((a) -> {
             responseContext.setEntityStream(new FilterInputStream(a) {