Move CountDown to After Target Method Call

Small adjustment to where the countdown latch is decremented to prevent test asserts from firing to soon.

spring-rabbit-test/src/main/java/org/springframework/amqp/rabbit/test/mockito/LatchCountDownAndCallRealMethodAnswer.java

@@ -41,8 +41,8 @@ public class LatchCountDownAndCallRealMethodAnswer implements Answer<Void> {
 
 	@Override
 	public Void answer(InvocationOnMock invocation) throws Throwable {
-		this.latch.countDown();
 		invocation.callRealMethod();
+		this.latch.countDown();
 		return null;
 	}