Increase Nginx fastcgi buffers (Docker)

docker/etc/nginx/nginx.conf

@@ -17,7 +17,10 @@ http {
     server_tokens      off;
     access_log         off;
     error_log          /dev/stderr;
-
+    
+    fastcgi_buffers 16 16k;                                                                                                                                       
+    fastcgi_buffer_size 32k;
+    
     server {
         listen       80;
         listen       443 ssl;