Make Mastodon services listen on private IP in prod

And allow access to them from the private network

site-cookbooks/kosmos-mastodon/templates/default/mastodon-streaming.systemd.service.erb

@@ -6,6 +6,7 @@ Type=simple
 User=<%= @user %>
 WorkingDirectory=<%= @app_dir %>
 Environment="NODE_ENV=production"
+Environment="BIND=<%= @bind %>"
 Environment="PORT=<%= @port %>"
 ExecStart=/usr/bin/npm run start
 TimeoutSec=15