Use .setStatus in ResponseStatusExceptionResolver

Before this change ResponseStatusExceptionResolver always used
.sendError despite the javadoc on @ResponseStatus#code. This was
perhaps justifiable from a HandlerExceptionResolver. Nevertheless
.setStatus should be more REST API friendly while still marking
the response as an error.

Issue: SPR-11193

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/annotation/ResponseStatusExceptionResolver.java

@@ -101,7 +101,7 @@ public class ResponseStatusExceptionResolver extends AbstractHandlerExceptionRes
 			reason = this.messageSource.getMessage(reason, null, reason, LocaleContextHolder.getLocale());
 		}
 		if (!StringUtils.hasLength(reason)) {
-			response.sendError(statusCode);
+			response.setStatus(statusCode);
 		}
 		else {
 			response.sendError(statusCode, reason);