ARTEMIS-945 - fix test and queue delete

https://issues.apache.org/jira/browse/ARTEMIS-945

artemis-server/src/main/java/org/apache/activemq/artemis/core/server/impl/QueueManagerImpl.java

@@ -34,6 +34,13 @@ public class QueueManagerImpl implements QueueManager {
       @Override
       public void run() {
          Queue queue = server.locateQueue(queueName);
+         //the queue may already have been deleted and this is a result of that
+         if (queue == null) {
+            if (ActiveMQServerLogger.LOGGER.isDebugEnabled()) {
+               ActiveMQServerLogger.LOGGER.debug("pno queue to delete \"" + queueName + ".\"");
+            }
+            return;
+         }
          SimpleString address = queue.getAddress();
          AddressSettings settings = server.getAddressSettingsRepository().getMatch(address.toString());
          long consumerCount = queue.getConsumerCount();

tests/integration-tests/src/test/java/org/apache/activemq/artemis/tests/integration/amqp/ProtonTest.java

@@ -830,7 +830,7 @@ public class ProtonTest extends ProtonTestBase {
          Wait.waitFor(new Wait.Condition() {
             @Override
             public boolean isSatisfied() throws Exception {
-               return amqpConnection.isClosed();
+               return receiver.isClosed();
             }
          });
          assertTrue(receiver.isClosed());