IPVS fix

In accordance with the logic for SD, remove the ipvs rules
only when there is no more endpoints using the IP

Signed-off-by: Flavio Crisciani <flavio.crisciani@docker.com>

service_common.go

@@ -342,7 +342,7 @@ func (c *controller) rmServiceBinding(svcName, svcID, nID, eID, containerName st
 
 	// Remove loadbalancer service(if needed) and backend in all
 	// sandboxes in the network only if the vip is valid.
-	if len(vip) != 0 {
+	if len(vip) != 0 && entries == 0 {
 		n.(*network).rmLBBackend(ip, vip, lb.fwMark, ingressPorts, rmService)
 	}