Fixing the following issues:

Notice: Undefined property: stdClass::$response in /wp-content/plugins/pronamic-client/classes/Pronamic/WP/ClientPlugin/Updater.php on line 85

Warning: array_merge() [function.array-merge]: Argument #1 is not an array in /wp-content/plugins/pronamic-client/classes/Pronamic/WP/ClientPlugin/Updater.php on line 85