fix toc bug

Author: mrbullwinkle

articles/azure-monitor/toc.yml

@@ -748,8 +748,6 @@
       href: insights/containers.md
   - name: Monitor other resources
     items:
-    - name: Key Vault
-      href: insights/key-vault-insights-overview.md
     - name: Storage
       items:
       - name: Azure Monitor for Storage