[Sync-En] gmp, image: update gmp_random_seed example for PHP 8 and explain imagepng filters with system libgd - #1482

[Sync-En] gmp, image: update gmp_random_seed example for PHP 8 and explain imagepng filters with system libgd#1482

julionc merged 2 commits into

php:masterphp/doc-es:masterfrom

lacatoire:sync-en/gmp-imagepnglacatoire/doc-es:sync-en/gmp-imagepngCopy head branch name to clipboard