Add marble diagram to the Single.filter method (ReactiveX#6075)

* Add marble diagram to the Single.filter method

* Use correct marble diagram URL for Single.filter method

Author: UMFsimke

src/main/java/io/reactivex/Single.java

@@ -2373,7 +2373,7 @@ public final Single<T> doOnDispose(final Action onDispose) {
      * Filters the success item of the Single via a predicate function and emitting it if the predicate
      * returns true, completing otherwise.
      * <p>
-     * <img width="640" height="310" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/filter.png" alt="">
+     * <img width="640" height="457" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/Single.filter.png" alt="">
      * <dl>
      *  <dt><b>Scheduler:</b></dt>
      *  <dd>{@code filter} does not operate by default on a particular {@link Scheduler}.</dd>