add protocol header for proxied services (#1076)

appmgr/src/net/nginx.conf.template

@@ -7,6 +7,7 @@ server {{
     location / {{
         proxy_pass http://{app_ip}:{internal_port}/;
         proxy_set_header Host $host;
+        proxy_set_header X-Forwarded-Proto $scheme;
         client_max_body_size 0;
         proxy_request_buffering off;
         proxy_buffering off;