Fixes a bug when doing a HLOOKUP on a single row.
```php
<?php
require 'vendor/autoload.php';
use PhpOffice\PhpSpreadsheet\Spreadsheet;
$spreadsheet = new Spreadsheet();
$sheet = $spreadsheet->getActiveSheet();
/**
* Single row.
*/
$singleRow = "=HLOOKUP(10, {5, 10, 15}, 1, 0)";
$sheet->getCell('A1')->setValue($singleRow);
// Should echo 10, but echos '#N/A' and some PHP notices and warnings.
echo $sheet->getCell('A1')->getCalculatedValue() . PHP_EOL;
/**
* Multiple rows.
*/
$multipleRows = "=HLOOKUP(10, {5, 10, 15; 20, 25, 30}, 1, 0)";
$sheet->getCell('A2')->setValue($multipleRows);
// Should echo: 10 and also does.
echo $sheet->getCell('A2')->getCalculatedValue() . PHP_EOL;
```
Co-authored-by: Mark Baker <mark@lange.demon.co.uk>