Fix Resource Server clock skew default value in docs

Closes gh-6611

Author: eleftherias

docs/manual/src/docs/asciidoc/_includes/reactive/oauth2/resource-server.adoc

@@ -510,7 +510,7 @@ ReactiveJwtDecoder jwtDecoder() {
 ----
 
 [NOTE]
-By default, Resource Server configures a clock skew of 30 seconds.
+By default, Resource Server configures a clock skew of 60 seconds.
 
 [[webflux-oauth2resourceserver-validation-custom]]
 ==== Configuring a Custom Validator

docs/manual/src/docs/asciidoc/_includes/servlet/oauth2/oauth2-resourceserver.adoc

@@ -531,7 +531,7 @@ JwtDecoder jwtDecoder() {
 ----
 
 [NOTE]
-By default, Resource Server configures a clock skew of 30 seconds.
+By default, Resource Server configures a clock skew of 60 seconds.
 
 [[oauth2resourceserver-jwt-validation-custom]]
 ==== Configuring a Custom Validator