Remove key-method 1

Remove key-method 1

Key-method 1 is only needed to talk to pre OpenVPN 2.0 clients.

Patch V2: Fix style. Make V1 op codes illegal, remove all code handling
          v1 op codes and give a good warning message if we encounter
          them in the legal op codes pre-check.

Patch V3: Add a bit more comments in the existing methods.

Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: David Sommerseth <davids@openvpn.net>
Message-Id: <20200721100128.9850-1-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg20516.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>