apnscp PHP 7.2 migration notes

apnscp upstream is migrating to PHP 7.2 Friday, September 14 for improved performance and stability quirks that have been noted during its development cycle. In this release, some unnecessary configuration collisions are also resolved, which requires running the playbook manually.

This is a companion discussion topic for the original entry at https://hq.apiscp.com/apnscp-php-7-2-migration-notes/