fix http 502 when aquiring kc assets

Author: makemek

deployment/nginx/nginx.conf

@@ -126,15 +126,14 @@ http {
             # DONT remove this. It will cause upstream server to respond http 400
             # due to "connection" header is closed instead of keep-alive and incorrect host header
             proxy_set_header Connection "";
-            proxy_set_header Host $host;
+            proxy_set_header Host "";
         }
 
         location / {
             proxy_pass http://modcolle_servers;
-            proxy_set_header Host $host;
         }
 
         # error_page 404 /404.html;
         # error_page 500 502 503 504 /50x.html;
     }
-}
+}