SSL Mixed Content Issue

Hi! Nice work with your plugin and subscriber lists!!! I installed it on my site and every works perfectly at once.

However it gave me a Mixed Content issue with my SSL Certificate. I know, because uninstalling the plugin fixed the error.

I have latest version and make a Subscribe popup. No images, no custom CSS. Only a title and a text.

Could you take a look at this issue so is appear something important? thanks!

The page I need help with: [log in to see the link]