Make sure nginx doesn't close connection on slow event feed readers.

Author: nickygerritsen

provision-contest/ansible/roles/domserver/templates/nginx-domjudge.conf.j2

@@ -25,5 +25,6 @@ server {
 
 	add_header Strict-Transport-Security max-age=31556952;
 
+	send_timeout 36000s;
 	include /etc/nginx/snippets/domjudge-inner;
 }