Fix #544 ReplaySubject emits items received after onError

Author: benjchristensen

rxjava-core/src/main/java/rx/subjects/ReplaySubject.java

@@ -164,6 +164,9 @@ public void onError(Throwable e)
     public void onNext(T args)
     {
         synchronized (subscriptions) {
+            if (isDone) {
+                return;
+            }
             history.add(args);
             for (Observer<? super T> observer : new ArrayList<Observer<? super T>>(subscriptions.values())) {
                 observer.onNext(args);