fix typo

Author: Maisy

custom-error/README.adoc

@@ -106,7 +106,7 @@ public OAuth2UserService<OAuth2UserRequest, OAuth2User> oauth2UserService(WebCli
  DefaultOAuth2UserService delegate = new DefaultOAuth2UserService();
  return request -> {
  OAuth2User user = delegate.loadUser(request);
- if (!"github".equals(request.getClientRegistration.getRegistrationId())) {
+ if (!"github".equals(request.getClientRegistration().getRegistrationId())) {
 	return user;
  }
 
@@ -148,4 +148,4 @@ public WebClient rest(ClientRegistrationRepository clients, OAuth2AuthorizedClie
 ----
 
 TIP: Obviously the code above can be generalized to other authentication rules, some applicable to GitHub and some to other OAuth 2.0 providers.
-All you need is the `WebClient` and some knowledge of the provider's API.
+All you need is the `WebClient` and some knowledge of the provider's API.