lxd/firewall/drivers/drivers/xtables: NetworkClear updated to add new arguments
lxd/firewall/drivers/drivers/xtables: NetworkClear updated to add new arguments

Now supports removing network-specific chains in delete mode.

Signed-off-by: Thomas Parrott <6b778ce645fb0e3dde76d79eccad490955b1ae74@canonical.com>

hallyn/lxd,atxwebs/lxd,lxc/lxd,hallyn/lxd,lxc/lxd,lxc/lxd,stgraber/lxd,hallyn/lxd,lxc/lxd,stgraber/lxd,stgraber/lxd,stgraber/lxd,lxc/lxd,stgraber/lxd,atxwebs/lxd,atxwebs/lxd,lxc/lxd,stgraber/lxd,hallyn/lxd,hallyn/lxd,stgraber/lxd,atxwebs/lxd,hallyn/lxd,lxc/lxd