Fix minor issue in WebSocketHttpRequestHandler

Issue: SPR-10721

spring-websocket/src/main/java/org/springframework/web/socket/server/support/WebSocketHttpRequestHandler.java

@@ -65,7 +65,7 @@ public class WebSocketHttpRequestHandler implements HttpRequestHandler {
 		Assert.notNull(webSocketHandler, "webSocketHandler must not be null");
 		Assert.notNull(handshakeHandler, "handshakeHandler must not be null");
 		this.webSocketHandler = decorateWebSocketHandler(webSocketHandler);
-		this.handshakeHandler = new DefaultHandshakeHandler();
+		this.handshakeHandler = handshakeHandler;
 	}