Update UPGRADE.md [skip ci]

UPGRADE.md

@@ -12,7 +12,7 @@ Changes summary:
 
 ## 1.x to 2.0
 * `$columns` parameter of `Query::select()` and `Query::addSelect()` methods can also accept scalar values of `bool`, 
-  `float` or `int` types or array of scalar values. For example, `$query->select(1)` will be converted to `SELECT 1`.
+  `float` or `int` types or array with scalar values. For example, `$query->select(1)` will be converted to `SELECT 1`.
 
 ## Yii2 to 1.0
 * `Yiisoft\Db\Connection::$charset` has been removed. All supported PDO classes allow you to specify the connection