bgp: add dummy Flat methods to Extended Communities
bgp: add dummy Flat methods to Extended Communities

ramrunner/gobgp,tamihiro/gobgp,a16/gobgp,a16/gobgp,a16/gobgp,a16/gobgp,fujita/gobgp,ishidawataru/gobgp,j-kato/gobgp,fujita/gobgp,fujita/gobgp,a16/gobgp,j-kato/gobgp,osrg/gobgp,osrg/gobgp,j-kato/gobgp,Dipsingh/gobgp,tamihiro/gobgp,osrg/gobgp,fujita/gobgp,tamihiro/gobgp,osrg/gobgp,ishidawataru/gobgp,ramrunner/gobgp,Dipsingh/gobgp,tamihiro/gobgp,Dipsingh/gobgp,a16/gobgp,ishidawataru/gobgp,ramrunner/gobgp,a16/gobgp