finally fix the net-snmp4 build! tested also with 5.0-RELEASE-p3,
5.0-CURRENT and with OPENSSL_OVERWRITE_BASE too.
Thanks to Joe Marcus Clarke <firstname.lastname@example.org>,
Ade Lovett <email@example.com> and
Will Mitayai Keeso Rowe <firstname.lastname@example.org> who reported that problem.
I'll take this.
Committed, thanks a lot for your efforts!