Fix Bug #79296 ZipArchive::open fails on empty file

[remicollet]

Try to reduce the minor BC break introduce in libzip 1.6.0

See https://bugs.php.net/bug.php?id=79296

Above code seems quite ok...

$f = tempnam(sys_get_temp_dir(), 'xxx');
$zip = new ZipArchive();
$success = $zip->open($f);

Open for discussion, don't know if we should even try to fix this

[cmb69]

I think the reasoning behind nih-at/libzip#105 makes some sense, so we should at most fix this temporarily for BC reasons (i.e. this patch should target PHP-7.3+). In the long run (PHP 9?) we're likely better off to accept the behavioral change.

[remicollet]

@cmb69 thanks for your feedback which confirm my feeling.

Applied in 7.3+
Deprecattion added for 8.0 in a4d12f4