FIX: typo in sql escaping for pgsql
FIX: typo in sql escaping for pgsql

IgorNadj/silverstripe-shop-discount,burnbright/silverstripe-shop-discount,markguinn/silverstripe-shop-discount,IgorNadj/silverstripe-shop-discount,markguinn/silverstripe-shop-discount,burnbright/silverstripe-shop-discount