Consistent java.time setters on HttpHeaders and CorsConfiguration

Closes gh-22546

spring-web/src/test/java/org/springframework/web/cors/CorsConfigurationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2019 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -47,7 +47,7 @@ public class CorsConfigurationTests {
 		assertNull(config.getExposedHeaders());
 		config.setAllowCredentials(null);
 		assertNull(config.getAllowCredentials());
-		config.setMaxAge(null);
+		config.setMaxAge((Long) null);
 		assertNull(config.getMaxAge());
 	}