Fix wrong byte order of --dns server

Fix wrong byte order of --dns server

We already fixed it in commit 82fd89a04f, but
the fix got lost in 2dfc4f8.

tuntap_options require host byte order, and we store
dns servers in struct dns_server in network byte order,
what we got from getaddrinfo().

Fix (again) by converting to the host byte order.

Change-Id: I37ca672f05e9d77ec586fa28dadc6dc752e574fb
Signed-off-by: Lev Stipakov <lev@openvpn.net>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20250731152912.21826-1-gert@greenie.muc.de>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg32460.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>