Fix tls-auth mismatch OCC message when tls-cryptv2 is used.

Fix tls-auth mismatch OCC message when tls-cryptv2 is used.

A server with tls-cryptv2 and tls-auth produces the warning:

  WARNING: 'tls-auth' is present in local config but missing in remote
config, local='tls-auth'"

The tls-auth option has no argument so the strpefix with the space
included does not match it.

Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Steffan Karger <steffan@karger.me>
Message-Id: <20201211125957.7764-1-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg21358.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
(cherry picked from commit 15daa9886b64a8378a6c5d68f79076dc44095696)