fix tolerationsWhitelist annotation example

Author: danielkucera

content/en/docs/reference/access-authn-authz/admission-controllers.md

@@ -707,7 +707,7 @@ metadata:
   name: apps-that-need-nodes-exclusively
   annotations:
     scheduler.alpha.kubernetes.io/defaultTolerations: '[{"operator": "Exists", "effect": "NoSchedule", "key": "dedicated-node"}]'
-    scheduler.alpha.kubernetes.io/tolerationsWhitelist: '{"operator": "Exists", "effect": "NoSchedule", "key": "dedicated-node"}'
+    scheduler.alpha.kubernetes.io/tolerationsWhitelist: '[{"operator": "Exists", "effect": "NoSchedule", "key": "dedicated-node"}]'
 ```
 
 ### Priority {#priority}