package/php: security bump version to 7.4.18
Changelog: https://www.php.net/ChangeLog-7.php#7.4.18
Release notes: https://www.php.net/releases/7_4_18.php
Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
(cherry picked from commit ac3234acd872678abba11217a258e3037c4ab2a8)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>