macvlan: set proxy_arp in time of creating interface
macvlan: set proxy_arp in time of creating interface

Resolves CNI part of https://github.com/coreos/rkt/issues/1765
Second part would be adding similar lines into kvm flavored macvlan
support (in time of creating macvtap device).

kad/cni,squaremo/cni,containernetworking/plugins,containernetworking/plugins,luxas/cni,mcastelino/cni,appc/cni,containernetworking/cni,murat1985/cni,mcastelino/cni,kad/cni,steveeJ/cni,tangle329/cni,containernetworking/cni,squeed/plugins,tomdee/cni,tangle329/cni,achanda/cni,achanda/cni,rosenhouse/cni,tomdee/cni,aanm/cni,murat1985/cni,appc/cni,dcbw/cni,luxas/cni,dcbw/cni,aanm/cni,rosenhouse/cni,squeed/plugins,jonboulle/cni,squaremo/cni,jonboulle/cni,steveeJ/cni