remove isUnsubscribed call befor item emittion

src/main/java/rx/operators/OperatorSharedPreferenceChange.java

@@ -34,7 +34,6 @@ public void call(final Subscriber<? super String> subscriber) {
         final SharedPreferences.OnSharedPreferenceChangeListener listener = new SharedPreferences.OnSharedPreferenceChangeListener() {
             @Override
             public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
-                if(!subscriber.isUnsubscribed())
                 subscriber.onNext(key);
             }
         };