Update CompositeSubscriptionTest.java

Fix apparent typo, unsubscription of s2 was not checked and should have been.

Author: davidmoten

rxjava-core/src/test/java/rx/subscriptions/CompositeSubscriptionTest.java

@@ -238,7 +238,7 @@ public void testClear() {
         s.clear();
 
         assertTrue(s1.isUnsubscribed());
-        assertTrue(s1.isUnsubscribed());
+        assertTrue(s2.isUnsubscribed());
         assertFalse(s.isUnsubscribed());
 
         BooleanSubscription s3 = new BooleanSubscription();