Update opaque-token.adoc

Fixing yaml sample in Servlet and Reactive pages

docs/modules/ROOT/pages/reactive/oauth2/resource-server/opaque-token.adoc

@@ -26,13 +26,14 @@ You can specify where the introspection endpoint is:
 ====
 [source,yaml]
 ----
-security:
-  oauth2:
-    resourceserver:
-      opaque-token:
-        introspection-uri: https://idp.example.com/introspect
-        client-id: client
-        client-secret: secret
+spring:
+  security:
+    oauth2:
+      resourceserver:
+        opaque-token:
+          introspection-uri: https://idp.example.com/introspect
+          client-id: client
+          client-secret: secret
 ----
 ====
 

docs/modules/ROOT/pages/servlet/oauth2/resource-server/opaque-token.adoc

@@ -24,13 +24,14 @@ To specify where the introspection endpoint is, simply do:
 
 [source,yaml]
 ----
-security:
-  oauth2:
-    resourceserver:
-      opaque-token:
-        introspection-uri: https://idp.example.com/introspect
-        client-id: client
-        client-secret: secret
+spring:
+  security:
+    oauth2:
+      resourceserver:
+        opaque-token:
+          introspection-uri: https://idp.example.com/introspect
+          client-id: client
+          client-secret: secret
 ----
 
 Where `https://idp.example.com/introspect` is the introspection endpoint hosted by your authorization server and `client-id` and `client-secret` are the credentials needed to hit that endpoint.