Fix syntax error in mssql.initial.sql (#6097)

CHANGELOG

@@ -8,6 +8,7 @@ CHANGELOG Roundcube Webmail
 - Fix PHP warning "idn_to_utf8(): INTL_IDNA_VARIANT_2003 is deprecated" with PHP 7.2 (#6075)
 - Fix bug where Archive folder wasn't auto-created on login with create_default_folders=true
 - Fix performance issue when parsing malformed and long Date header (#6087)
+- Fix syntax error in mssql.initial.sql (#6097)
 
 RELEASE 1.3.3
 -------------

SQL/mssql.initial.sql

@@ -222,7 +222,7 @@ GO
 
 ALTER TABLE [dbo].[cache] ADD 
 	CONSTRAINT [DF_cache_user_id] DEFAULT ('0') FOR [user_id],
-	CONSTRAINT [DF_cache_cache_key] DEFAULT ('') FOR [cache_key],
+	CONSTRAINT [DF_cache_cache_key] DEFAULT ('') FOR [cache_key]
 GO
 
 ALTER TABLE [dbo].[cache_index] ADD