Make processing shorter in Spring AMQP tutorial 2

Or the consumer application may stop before all
messages are processed, making the user believe
some messages have been lost.

spring-amqp/src/main/java/org/springframework/amqp/tutorials/tut2/Tut2Receiver.java

@@ -45,7 +45,7 @@ public class Tut2Receiver {
 	private void doWork(String in) throws InterruptedException {
 		for (char ch : in.toCharArray()) {
 			if (ch == '.') {
-				Thread.sleep(1000);
+				Thread.sleep(500);
 			}
 		}
 	}