Check if gateways key exists and it is an array, to fix the following issue:

[Fri Jan 31 13:29:17 2014] [error] [client 80.69.69.100] FastCGI: server "/var/run/php-fpm/php54/php-cgi" stderr: PHP message: PHP Warning:  Invalid argument supplied for foreach() in /wp-content/plugins/wp-pronamic-ideal-develop/views/config-edit.php on line 593, referer: /wp-admin/edit.php?post_type=pronamic_gateway