Merge pull request #3656 from halkyon/nginx_buffers

Adding appropriate nginx fastcgi buffer config required for admin

docs/en/installation/nginx.md

@@ -86,6 +86,9 @@ But enough of the disclaimer, on to the actual configuration — typically in `n
 			fastcgi_index  index.php;
 			fastcgi_param  SCRIPT_FILENAME $document_root$fastcgi_script_name;
 			include        fastcgi_params;
+			fastcgi_buffer_size 32k;
+			fastcgi_busy_buffers_size 64k;
+			fastcgi_buffers 4 32k;
 		}
 	}