Fix typo

Author: rwestMSFT

docs/database-engine/configure-windows/ucs-flow-control-sp-configure.md

@@ -67,7 +67,7 @@ EXEC sp_configure 'show advanced options', 1;
 RECONFIGURE;
 GO
 
-EXEC sp_configure `max ucs send boxcars`, 1234;
+EXEC sp_configure 'max ucs send boxcars', 1234;
 RECONFIGURE;
 GO
 ```