Fix DefaultErrorViewResolver after HttpStatus changes

Since SPR-16898, `HttpStatus.toString()` has changed and we should
instead rely on `HttpStatus.value()` to get the HTTP status number.

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/servlet/error/DefaultErrorViewResolver.java

@@ -102,7 +102,7 @@ public class DefaultErrorViewResolver implements ErrorViewResolver, Ordered {
 	@Override
 	public ModelAndView resolveErrorView(HttpServletRequest request, HttpStatus status,
 			Map<String, Object> model) {
-		ModelAndView modelAndView = resolve(String.valueOf(status), model);
+		ModelAndView modelAndView = resolve(String.valueOf(status.value()), model);
 		if (modelAndView == null && SERIES_VIEWS.containsKey(status.series())) {
 			modelAndView = resolve(SERIES_VIEWS.get(status.series()), model);
 		}