plugins/range: Remove setup6 function for range

Signed-off-by: Anatole Denis <anatole@unverle.fr>

plugins/range/plugin.go

@@ -28,7 +28,6 @@ var log = logger.GetLogger("plugins/range")
 // Plugin wraps plugin registration information
 var Plugin = plugins.Plugin{
 	Name:   "range",
-	Setup6: setup6,
 	Setup4: setup4,
 }
 
@@ -116,12 +115,6 @@ func Handler4(req, resp *dhcpv4.DHCPv4) (*dhcpv4.DHCPv4, bool) {
 	return resp, false
 }
 
-func setup6(args ...string) (handler.Handler6, error) {
-	// TODO setup function for IPv6
-	log.Warning("not implemented for IPv6")
-	return Handler6, nil
-}
-
 func setup4(args ...string) (handler.Handler4, error) {
 	_, h4, err := setupRange(false, args...)
 	return h4, err