Update TOC.yml

Author: cherylmc

articles/vpn-gateway/TOC.yml

@@ -51,8 +51,8 @@
     href: about-zone-redundant-vnet-gateways.md
   - name: Security
     items:
-      - name: Security baseline
-        href: /security/benchmark/azure/baselines/vpn-gateway-security-baseline?toc=/azure/vpn-gateway/TOC.json
+    - name: Security baseline
+      href: /security/benchmark/azure/baselines/vpn-gateway-security-baseline?toc=/azure/vpn-gateway/TOC.json
   - name: Backend Connectivity Interoperability
     items:
     - name: Preface and Test Setup