The kernel config option CONFIG_NET_UDP_TUNNEL is not visible and can
not directly be activated. When kmod-udptunnel4 or kmod-udptunnel6 are
build these packages could be empty when no other kernel module selects
CONFIG_NET_UDP_TUNNEL.
Reported-by: Baptiste Jonglez <baptiste@bitsofnetworks.org>
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
