update change log.

laravel/documentation/changes.md

@@ -31,6 +31,7 @@
 ## Laravel 3.2.1
 
 - Fixed bug in cookie retrieval when cookie is set on same request.
+- Fixed bug in SQL Server grammar for primary keys.
 
 <a name="upgrade-3.2.1"></a>
 ## Upgrading From 3.2