Warn user if INFO control command is too long

Warn user if INFO control command is too long

"INFO_PRE,..." command length is limited to 256 bytes. If the server
implementation pushes command which is too long, warn the user and
don't send the truncated command to a management client.

Change-Id: If3c27a2a2ba24f2af0e3e3c95eea57ed420b2542
Signed-off-by: Lev Stipakov <lev@openvpn.net>
Acked-by: Frank Lichtenheld <frank@lichtenheld.com>
Message-Id: <20230922105055.37969-1-frank@lichtenheld.com>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg27062.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>