ARTEMIS-2788 clear openwire producer exchange, created on send, on producer close event

artemis-protocols/artemis-openwire-protocol/src/main/java/org/apache/activemq/artemis/core/protocol/openwire/OpenWireConnection.java

@@ -1211,6 +1211,9 @@ public class OpenWireConnection extends AbstractRemotingConnection implements Se
                ss.removeProducer(id);
             }
          }
+         synchronized (producerExchanges) {
+            producerExchanges.remove(id);
+         }
          return null;
       }