Fixed an issue where hundreds of Warning are displayed while define('WP_...

Hi, I was recently using your pluging and have been for sometime.

I've been performing some test with WordPress 3.9 using your plugin and notice that when your plugin is enabled and wp_debug is set to true. Certain pages on the admin side can generate hundreds possibly thousands of warning for "first argument of wpdb::prepare should have a placeholder".

Summary of the change:
- Orignial: $wpdb->get_col($wpdb->prepare("SELECT domain FROM " . $wpdb->blogs, NULL));
- New:      $wpdb->get_col($wpdb->prepare("SELECT domain FROM %d", $wpdb->blogs));

For information see the ticket that introduced the notice in WP3.9 https://core.trac.wordpress.org/ticket/25604

See my change log for more information.

My configuration:
- WP3.9.1
- Multisite enabled
- WordPress-HTTPS was networked enabled 

Anyway I hope that helps!

Thanks and kind regards,

Steven