multi.c: use mi->cc_config instead of config variable

multi.c: use mi->cc_config instead of config variable

Commit ("Remove parameter config from multi_client_connect_mda") has
removed the config variable in favour of mi->cc_config, however one
occurence was not changed.

Fix it now by properly using mi->cc_config.

Signed-off-by: Antonio Quartulli <a@unstable.cc>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20200701140517.11176-1-a@unstable.cc>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg20180.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>