Support for upstream ssl proxy hosts

rootfs/etc/nginx/nginx.conf

@@ -54,6 +54,11 @@ http {
   # Dynamically generated resolvers file
   include /etc/nginx/conf.d/include/resolvers.conf;
 
+  # Default upstream scheme
+  map $host $forward_scheme {
+    default http;
+  }
+
   # Files generated by NPM
   include /etc/nginx/conf.d/*.conf;
   include /data/nginx/proxy_host/*.conf;