// ↓ここを追加
        if (empty($arrDeliv['deliv_fee']) || !is_array($arrDeliv['deliv_fee'])) { 
            $arrDeliv['deliv_fee'] = array();
        }
        // ↑ここを追加
        foreach ($arrDeliv['deliv_fee'] as $value) {
            $deliv_fee[]['fee'] = $value['fee'];
        }