security/py-acme-tiny: update to 5.0.2 and take maintainership

While here, removed the USE=ssl. Because the script does not use the
Python ssl module or link against any OpenSSL libraries. It only calls
the external openssl command via subprocess (_cmd(["openssl").

Changelog: https://github.com/diafygi/acme-tiny/releases/tag/5.0.2

PR: 288560
Reported by: Atanu Biswas <atanubiswas484@gmail.com> (new maintainer)