fix: update dummy bootstrap example

misc/bootstrap.d/dummy.yml

@@ -19,7 +19,8 @@ layers:
   #       clientId: my-client-id
   #       clientSecret: my-client-id
   #       issuerURL: https://forge.cadoles.com/
-  #       postLogoutRedirectURL: http://localhost:8080
+  #       postLogoutRedirectURLs:
+  #         - http://localhost:8080
   #       scopes: ["profile", "openid", "email"]
   #       authParams:
   #         acr_values: "eidas2"