[VOL-4513] Always push events on the queue, even if they are duplicates

In the case of an Add -> Delete -> Add that are received very quickly,
we might try to add the second Add to the queue before the first one is removed.

If that's the case the second Add won't be processed and we'll be left in an inconsistent state.
The event handling is idempotent anyway so there's no issue in duplicating them.

Change-Id: Iebc28a147eff9a061148bc72a9878b52a62e113d
diff --git a/impl/src/test/java/org/opencord/olt/impl/OltTest.java b/impl/src/test/java/org/opencord/olt/impl/OltTest.java
index e8a76d0..0448f9d 100644
--- a/impl/src/test/java/org/opencord/olt/impl/OltTest.java
+++ b/impl/src/test/java/org/opencord/olt/impl/OltTest.java
@@ -194,12 +194,11 @@
         LinkedBlockingQueue<DiscoveredSubscriber> spiedQueue = spy(q);
         component.eventsQueues.put(cp, spiedQueue);
 
-        // trying to add the same event twice should result in a single item in the queue
         component.addSubscriberToQueue(sub);
         component.addSubscriberToQueue(sub);
 
-        verify(spiedQueue, times(1)).add(sub);
-        Assert.assertEquals(1, spiedQueue.size());
+        verify(spiedQueue, times(2)).add(sub);
+        Assert.assertEquals(2, spiedQueue.size());