dataprovider: reset orderBy when counting

strict sql dbms like postgres would fail otherwise

framework/yii/data/ActiveDataProvider.php

@@ -158,7 +158,7 @@ class ActiveDataProvider extends BaseDataProvider
 			throw new InvalidConfigException('The "query" property must be an instance of a class that implements the QueryInterface e.g. yii\db\Query or its subclasses.');
 		}
 		$query = clone $this->query;
-		return (int) $query->limit(-1)->offset(-1)->count($this->db);
+		return (int) $query->limit(-1)->offset(-1)->orderBy([])->count($this->db);
 	}
 
 	/**