Merge pull request #3176 from chiragshah6/evpn_dev

zebra: duplicate address detection and dampening

diff --cc bgpd/bgp_evpn_vty.c
Simple merge

diff --cc bgpd/bgp_zebra.c
Simple merge

diff --cc bgpd/bgpd.c
Simple merge

diff --cc bgpd/bgpd.h
Simple merge