Remove support for NTLM v1 proxy authentication

Remove support for NTLM v1 proxy authentication

Due to the limitation of the protocol it is not
considered secure. Better to use basic auth instead
of a false sense of security. NTLM v2 remains
supported for now.

Change-Id: I0dcb2dac4136f194da7050a8ea8495e9faba9dd9
Signed-off-by: Frank Lichtenheld <frank@lichtenheld.com>
Acked-by: Arne Schwabe <arne-openvpn@rfc2549.org>
Message-Id: <20231230143733.4426-1-gert@greenie.muc.de>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg27862.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>