Recent changes around the configuration tree broke the current
implementation of the lxc-netstat.

Instead of retrieving the init_pid in the /var/lxc/<name>/...,
pick one in the cgroup tasks list.

There is still a restriction with this command making impossible
to run it as non-root, any idea is welcome :(
Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>