buildroot

lxc: bump version

[Thomas: switch back to a tarball from
https://linuxcontainers.org/downloads/ instead of
github. Unfortunately, even though the tarball has the configure
script generated, we still need to autoreconf since we're patching
configure.ac.]

Signed-off-by: Maxime Hadjinlian <maxime.hadjinlian@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>