Source format and clean-up

spring-boot-samples/spring-boot-sample-jetty/src/test/java/org/springframework/boot/sample/jetty/SampleJettyApplicationTests.java

@@ -51,7 +51,7 @@ public class SampleJettyApplicationTests {
 						new Callable<ConfigurableApplicationContext>() {
 							@Override
 							public ConfigurableApplicationContext call() throws Exception {
-								return (ConfigurableApplicationContext) SpringApplication
+								return SpringApplication
 										.run(SampleJettyApplication.class);
 							}
 						});