Alter proxy headers for proxying from nginx to tusd server

currently, uploads to tusd fails because tusd is HTTP GETting chunk
using non https url. We need to get it to use https url.

the new settings is the recommended ones from tusd:
tus/tusd#86

ops/configuration/nginx-conf/sites/staging/gigadb.staging.https.conf

@@ -59,7 +59,9 @@ server {
         client_max_body_size     0;
 
         # proxy_set_header Host       $host:$server_port;
-        proxy_set_header Host       $http_host;
+        # proxy_set_header Host       $http_host;
+        proxy_set_header Host $host;
+        proxy_set_header X-Real-IP $remote_addr;
     }
 
     location ~ /\.ht {