Kube-proxy not starting

I am following kelsey hightower article on LXC containers (https://github.com/kelseyhightower)

Everything works perfectly except kube-proxy which doesn’t come online.
here is error message
Jul 15 17:56:13 worker1 kube-proxy[9428]: I0715 17:56:13.130340 9428 server_others.go:143] Using iptables Proxier.

Jul 15 17:56:13 worker1 kube-proxy[9428]: I0715 17:56:13.131638 9428 server.go:534] Version: v1.15.3

Jul 15 17:56:13 worker1 kube-proxy[9428]: I0715 17:56:13.135578 9428 conntrack.go:52] Setting nf_conntrack_max to 196608

Jul 15 17:56:13 worker1 kube-proxy[9428]: F0715 17:56:13.135604 9428 server.go:449] strconv.Atoi: parsing “”: invalid syntax

Jul 15 17:56:13 worker1 systemd[1]: kube-proxy.service: Main process exited, code=exited, status=255/n/a

Jul 15 17:56:13 worker1 systemd[1]: kube-proxy.service: Failed with result ‘exit-code’.

Cluster information:

kubectl version --short
Client Version: v1.15.3
Server Version: v1.15.3

Installation method: Kelsey Hightower - Hard way on LXD 3.0.3
Host OS: Ubuntu 18.04
CNI and version: v0.8.2
CRI and version: containerd 1.2.9