table/path: net.IP.IsUnspecified() instead of isZero()
table/path: net.IP.IsUnspecified() instead of isZero()

Signed-off-by: IWASE Yusuke <bb80e84cc9f5a8f01385872ee89032beb5d4eba7@gmail.com>

a16/gobgp,a16/gobgp,j-kato/gobgp,osrg/gobgp,j-kato/gobgp,tamihiro/gobgp,tamihiro/gobgp,fujita/gobgp,j-kato/gobgp,a16/gobgp,a16/gobgp,osrg/gobgp,fujita/gobgp,a16/gobgp,fujita/gobgp,tamihiro/gobgp,tamihiro/gobgp,fujita/gobgp,a16/gobgp,a16/gobgp,osrg/gobgp,osrg/gobgp