Clean up warnings in spring-test

spring-test/src/test/java/org/springframework/test/web/servlet/samples/standalone/resultmatchers/HeaderAssertionTests.java

@@ -216,7 +216,6 @@ public class HeaderAssertionTests {
 
 
 	@Controller
-	@SuppressWarnings("unused")
 	private static class PersonController {
 
 		private long timestamp;