PHP Fatal error when cron w/ no wikis

To reproduce:

In a clean multisite child site, activate the Wiki plugin
Don't create any wikis
Run the WP cron from the command line
wp-cli.phar --skip-themes cron event run jetpack_clean_nonces wp_scheduled_delete wp_scheduled_auto_draft_delete --url="/mychildblog"

I get this error;
PHP Fatal error: Call to a member function get_setting() on a non-object in /home1l/wordpres/wordpress-0.0.1-20160229.162321-1d/wp-content/plugins/wiki/lib/classes/WikiWidget.php on line 8

Can you please add a check in that constructor? Something like:
if(!is_object($wiki) || !($wiki instanceof Wiki) {
return;
}