Restore all/accept_redirects and default/forwarding after
all/forwarding as the last can influence the former two.
(see inet_forward_change in kernel)

# sysctl -w net.ipv4.conf.all.forwarding=1
net.ipv4.conf.all.forwarding = 1
# sysctl -w net.ipv4.conf.default.forwarding=1
net.ipv4.conf.default.forwarding = 1
# sysctl -w net.ipv4.conf.all.forwarding=0
net.ipv4.conf.all.forwarding = 0
# sysctl net.ipv4.conf.default.forwarding
net.ipv4.conf.default.forwarding = 0

Trigered with netns-dev test in VZ7CT with vzlinux-6-x86_64 template
v2:quirk accept_redirects instead of duplicate entries in devconfs
Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>