Log Message:
TLSv1.2 support for mail/imapproxy

The change is from upstream with minor tweaks: use SSLv23_client_method()
that negociate highest possible protocol instead of TLSv1_client_method()
that can only do TLSv1.0. Insecure SSLv2 and SSLv3 are disabled through
SSL_CTX_set_options().

Approved by Thomas Klausner <wiz@NetBSD.org> on behalf of pksrc-pmc