Restore also ping related options on a reconnect

Restore also ping related options on a reconnect

This fixes the issue that if a client reconnects the next connection
entries inherits the keepalive settings that were pushed or set by
the previous entry. Since UDP+PULL entries have an implicit 120s
timeout, this timeout also got applied to a TCP session after an
UDP entry.

Patch v2: rebase on master

Reported-By: Jan Just Keijser <janjust@nikhef.nl>
Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Antonio Quartulli <antonio@openvpn.net>
Message-Id: <20210317160038.25828-3-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg21675.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
(cherry picked from commit 5a2ed714d14acb2312d27fe40e300be96d970c27)