fix: update privileges

Author: 0xPoe

sql-statements/sql-statement-refresh-stats.md

@@ -89,7 +89,7 @@ ClusterOption ::=
 
 ## Privileges
 
-To execute `REFRESH STATS`, you must have the `SELECT` privilege on every targeted table. If you do not have sufficient privileges, TiDB returns an error and aborts the statement.
+To execute `REFRESH STATS`, you must either have the `RESTORE_ADMIN` privilege or hold `SELECT` on every targeted table. If you do not have sufficient privileges, TiDB returns an error and aborts the statement.
 
 ## MySQL compatibility