Update JdkClientHttpRequest javadoc

This commit updates `JdkClientHttpRequest.TimeoutHandler` javadoc to
reference up-to-date JDK issue that tracks improvements to HTTP client's
request timeout handling.

Signed-off-by: Vedran Pavic <[email protected]>

Author: vpavic

spring-web/src/main/java/org/springframework/http/client/JdkClientHttpRequest.java

@@ -254,7 +254,7 @@ public ByteBuffer map(byte[] b, int off, int len) {
 
 	/**
 	 * Temporary workaround to use instead of {@link HttpRequest.Builder#timeout(Duration)}
-	 * until <a href="https://bugs.openjdk.org/browse/JDK-8258397">JDK-8258397</a>
+	 * until <a href="https://bugs.openjdk.org/browse/JDK-8208693">JDK-8208693</a>
 	 * is fixed. Essentially, create a future with a timeout handler, and use it
 	 * to close the response.
 	 * @see <a href="https://mail.openjdk.org/pipermail/net-dev/2021-October/016672.html">OpenJDK discussion thread</a>