Make sure the parent 'responseFuture' CompletableFuture is completed.
This ensures that the jettyRequest.abort() operation is actually performed.

Current situation prevent this code to be ever called as only the chained CompletableFuture is completed.

connectors/jetty-connector/src/main/java/org/glassfish/jersey/jetty/connector/JettyConnector.java

diff --git a/connectors/jetty-connector/src/main/java/org/glassfish/jersey/jetty/connector/JettyConnector.java b/connectors/jetty-connector/src/main/java/org/glassfish/jersey/jetty/connector/JettyConnector.java
index 1456d4b..89a0c05 100644
--- a/connectors/jetty-connector/src/main/java/org/glassfish/jersey/jetty/connector/JettyConnector.java
+++ b/connectors/jetty-connector/src/main/java/org/glassfish/jersey/jetty/connector/JettyConnector.java
@@ -392,8 +392,8 @@
         final AtomicBoolean callbackInvoked = new AtomicBoolean(false);
         final Throwable failure;
         try {
-            final CompletableFuture<ClientResponse> responseFuture =
-                    new CompletableFuture<ClientResponse>().whenComplete(
+            final CompletableFuture<ClientResponse> responseFuture = new CompletableFuture<ClientResponse>();
+            responseFuture.whenComplete(
                             (clientResponse, throwable) -> {
                                 if (throwable != null && throwable instanceof CancellationException) {
                                     // take care of future cancellation