abstractions/openssl: allow reading /etc/ssl/openssl-*.cnf

openSUSE Tumbleweed uses /etc/ssl/openssl-1_1.cnf to make the migration to openssl 3 possible.

References: https://bugzilla.opensuse.org/show_bug.cgi?id=1207911

I propose this patch for at least 3.1 and master, ideally for all branches (as long as it can easily be merged)