Update version in Javadoc

Author: acogoluegnes

src/main/java/com/rabbitmq/perf/RelaxedExceptionHandler.java

@@ -31,7 +31,7 @@
  * which are not useful here, so this exception handler is a bit more
  * relaxed for those logs.
  *
- * @since 2.4.1
+ * @since 2.5.0
  */
 public class RelaxedExceptionHandler extends DefaultExceptionHandler {
 

src/main/java/com/rabbitmq/perf/ShutdownService.java

@@ -31,7 +31,7 @@
  * individually, and/or call all of them (in LIFO order) with
  * the {@link #close()} method.
  *
- * @since 2.4.1
+ * @since 2.5.0
  */
 public class ShutdownService implements AutoCloseable {