Fix syntax in WebFlux Validation example

Closes gh-27907

src/docs/asciidoc/web/webflux.adoc

@@ -3845,7 +3845,7 @@ as the following example shows:
 	public class WebConfig implements WebFluxConfigurer {
 
 		@Override
-		public Validator getValidator(); {
+		public Validator getValidator() {
 			// ...
 		}