Fix race in test

- the second confirmation could arrive before the latch was counted down,
  resulting in an NPE and failed test.

Author: garyrussell

spring-rabbit/src/test/java/org/springframework/amqp/rabbit/core/RabbitTemplatePublisherCallbacksIntegrationTests3.java

@@ -60,10 +60,10 @@ public void testRepublishOnNackThreadNoExchange() throws Exception {
 		final RabbitTemplate template = new RabbitTemplate(cf);
 		final CountDownLatch confirmLatch = new CountDownLatch(2);
 		template.setConfirmCallback((cd, a, c) -> {
-			if (confirmLatch.getCount() == 2) {
+			confirmLatch.countDown();
+			if (confirmLatch.getCount() == 1) {
 				template.convertAndSend(QUEUE1, ((MyCD) cd).payload);
 			}
-			confirmLatch.countDown();
 		});
 		template.convertAndSend("bad.exchange", "junk", "foo", new MyCD("foo"));
 		assertThat(confirmLatch.await(10, TimeUnit.SECONDS)).isTrue();