Update monitoring-performance-by-using-the-query-store.md

Removed extra line of code.

Author: julieMSFT

docs/relational-databases/performance/monitoring-performance-by-using-the-query-store.md

@@ -45,7 +45,6 @@ monikerRange: "=azuresqldb-current||>=sql-server-2016||=sqlallproducts-allversio
 Use the **ALTER DATABASE** statement to enable the query store. For example:  
 
 ```sql  
-ALTER DATABASE AdventureWorks2012 SET QUERY_STORE = ON;  
 ALTER DATABASE AdventureWorks2012 SET QUERY_STORE (OPERATION_MODE = READ_WRITE); 
 ```