Fix Broken Link

Issue gh-10367

docs/modules/ROOT/pages/reactive/oauth2/index.adoc

@@ -4,5 +4,5 @@
 Spring Security provides OAuth2 and WebFlux integration for reactive applications.
 
 * xref:reactive/oauth2/login.adoc[OAuth2 Log In] - Authenticating with an OAuth2 or OpenID Connect 1.0 Provider
-* xref:reactive/oauth2/oauth2-client.adoc[OAuth2 Client] - Making requests to an OAuth2 Resource Server
+* xref:reactive/oauth2/client/index.adoc[OAuth2 Client] - Making requests to an OAuth2 Resource Server
 * xref:reactive/oauth2/resource-server/index.adoc[OAuth2 Resource Server] - Protecting a REST endpoint using OAuth2