fix mistake small [skip ci]

docs/guide/security-best-practices.md

@@ -56,7 +56,7 @@ SELECT * FROM user WHERE username = ''; DROP TABLE user; --'
 This is valid query that will search for users with empty username and then will drop `user` table most probably
 resulting in broken website and data loss (you've set up regular backups, right?).
 
-In Yii most of database querying happens via [Active Record](db-active-record.md) which properly uses PDO perpared
+In Yii most of database querying happens via [Active Record](db-active-record.md) which properly uses PDO prepared
 statements internally. In case of prepared statements it's not possible to manipulate query as was demonstrated above.
 
 Still, sometimes you need [raw queries](db-dao.md) or [query builder](db-query-builder.md). In this case you should use