Fix "neighbour: ndisc_cache: neighbor table overflow"
Fix "neighbour: ndisc_cache: neighbor table overflow"

The default ARP table size limit in the Linux kernel is 1024 entries.
Launching more than a thousand containers fills up the table
and new containers cannot get a network configuration.

Signed-off-by: Simos Xenitellis <a25f924930ba286655d33c04cb318091f9066e43@googlemail.com>

hallyn/lxd,Skarlso/lxd,lxc/lxd,hallyn/lxd,hallyn/lxd,stgraber/lxd,Skarlso/lxd,stgraber/lxd,lxc/lxd,atxwebs/lxd,Skarlso/lxd,hallyn/lxd,mjeanson/lxd,Skarlso/lxd,mjeanson/lxd,hallyn/lxd,atxwebs/lxd,stgraber/lxd,lxc/lxd,mjeanson/lxd,lxc/lxd,hallyn/lxd,lxc/lxd,atxwebs/lxd,stgraber/lxd,atxwebs/lxd,stgraber/lxd,stgraber/lxd,stgraber/lxd,lxc/lxd,lxc/lxd