[swarm-docker] Enable ipv6 on all interfaces.

Change-Id: Iab0f95be7f2886126b1d2c347beb9241843cc1ea
diff --git a/cmd/swarm_docker/swarm_docker.go b/cmd/swarm_docker/swarm_docker.go
index ad7102f..b136f09 100644
--- a/cmd/swarm_docker/swarm_docker.go
+++ b/cmd/swarm_docker/swarm_docker.go
@@ -297,7 +297,7 @@
 		config.Env = append(config.Env, fmt.Sprintf("%s=%v", k, v))
 	}
 	sysctlMap := make(map[string]string)
-	sysctlMap["net.ipv6.conf.qemu.disable_ipv6"] = "0"
+	sysctlMap["net.ipv6.conf.all.disable_ipv6"] = "0"
 	hostConfig := container.HostConfig{
 		CapAdd: strslice.StrSlice{"SYS_PTRACE"},
 		Resources: container.Resources{