Fix typo

Resolves #22241

Author: poutsma

src/docs/asciidoc/web/webflux-webclient.adoc

@@ -265,7 +265,7 @@ as the following example shows:
 	Mono<Person> result = client.get()
 			.uri("/persons/{id}", id).accept(MediaType.APPLICATION_JSON)
 			.retrieve()
-			.onStatus(HttpStatus::is4xxServerError, response -> ...)
+			.onStatus(HttpStatus::is4xxClientError, response -> ...)
 			.onStatus(HttpStatus::is5xxServerError, response -> ...)
 			.bodyToMono(Person.class);
 ----