ClusterManager: Implements support of remote clusters.

After this change users will be able to:
* Create cluster and add/remove servers to it
* Install apps on remote cluster
* Move already installed apps between clusters
* Apps running on server being removed will auto-migrate
  to another server from that same cluster

This is achieved by:
* Installing and running minimal version of dodo on remote cluster
* Ingress-nginx is installed automatically on new clusters
* Next to nginx we run VPN client in the same pod, so that
  default cluster can establish secure communication with it
* Multiple reverse proxies are configured to get to the
  remote cluster service from ingress installed on default cluster.

Next steps:
* Support remote clusters in dodo apps (prototype ready)
* Clean up old cluster when moving app to the new one. Currently
  old cluster keeps running app pods even though no ingress can
  reach it anymore.

Change-Id: Iffc908c93416d4126a8e1c2832eae7b659cb8044
diff --git a/charts/tailscale-proxy/templates/install.yaml b/charts/tailscale-proxy/templates/install.yaml
index 76241da..f85f753 100644
--- a/charts/tailscale-proxy/templates/install.yaml
+++ b/charts/tailscale-proxy/templates/install.yaml
@@ -64,8 +64,10 @@
         #       key: key
         - name: TS_HOSTNAME
           value: {{ .Values.hostname }}
+        {{- if .Values.ipSubnet }}
         - name: TS_ROUTES
           value: {{ .Values.ipSubnet }}
+        {{- end }}
         - name: TS_EXTRA_ARGS
           value: --login-server={{ .Values.loginServer }}
         # volumeMounts: