openvpn version line: remove [IPv6], add [AEAD] if available

openvpn version line: remove [IPv6], add [AEAD] if available

Printing [IPv6] is no longer relevant information, as IPv6 support
is always build in.  So, "2.4 = has IPv6, always".

[AEAD] is relevant information, as the underlying SSL library might
be too old to have support for it (OpenSSL 0.9.x) and this eases
figuring out why NCP is not upgrading a connection to AES-256-GCM.

Trac #762

Signed-off-by: Gert Doering <gert@greenie.muc.de>
Acked-by: Steffan Karger <steffan.karger@fox-it.com>
Message-Id: <1478515852-17381-1-git-send-email-gert@greenie.muc.de>
URL: http://www.mail-archive.com/search?l=mid&q=1478515852-17381-1-git-send-email-gert@greenie.muc.de
Signed-off-by: Gert Doering <gert@greenie.muc.de>