DefaultSubscriber javadoc sample fix (#5407)

* change sample such that it compiles

* fix: remove assignment

Author: devisnik

src/main/java/io/reactivex/subscribers/DefaultSubscriber.java

@@ -50,9 +50,8 @@
  * @param <T> the value type
  *
  * <p>Example<code><pre>
- * Disposable d =
- *     Flowable.range(1, 5)
- *     .subscribeWith(new DefaultSubscriber&lt;Integer>() {
+ * Flowable.range(1, 5)
+ *     .subscribe(new DefaultSubscriber&lt;Integer>() {
  *         &#64;Override public void onStart() {
  *             System.out.println("Start!");
  *             request(1);
@@ -71,8 +70,6 @@
  *             System.out.println("Done!");
  *         }
  *     });
- * // ...
- * d.dispose();
  * </pre></code>
  */
 public abstract class DefaultSubscriber<T> implements FlowableSubscriber<T> {