C32224: Re-formatting metadata block

Hello, @stevestein,
Localization team has reported source content issue that causes localized version to have broken/different format compared to en-us version.  
"add --- on the first line to properly close the metadata"

Please review and merge the proposed file change to fix to target versions. If you make related fix in another PR  then share your PR number so we can confirm and close this PR.
Many thanks in advance.

Author: v-maudel

docs/relational-databases/event-classes/auto-stats-event-class.md

@@ -1,4 +1,5 @@
-title: "Auto Stats Event Class | Microsoft Docs"
+---
+title: "Auto Stats Event Class | Microsoft Docs"
 ms.custom: ""
 ms.date: "03/14/2017"
 ms.prod: sql