Fix broken anchor link in WebFlux refdoc

Author: nkjackzhang

src/docs/asciidoc/web-reactive.adoc

@@ -10,7 +10,7 @@
 This part of the documentation covers support for reactive stack, web applications built on a
 http://www.reactive-streams.org/[Reactive Streams] API to run on non-blocking
 servers such as Netty, Undertow, and Servlet 3.1+ containers. Individual chapters cover
-the <<webflux-module,Spring WebFlux>> framework,
+the <<webflux,Spring WebFlux>> framework,
 the reactive <<webflux-client,WebClient>>, support for <<webflux-test>>,
 and <<webflux-reactive-libraries>>. For Servlet stack, web applications, please see
 <<web.adoc#spring-web,Web on Servlet Stack>>.