Google has announced that it will display security warnings for all pages containing input forms. They already do this for input fields meant for passwords or credit card details, but in October it will apply to all possible input forms, and we have quite a few of those.
To prevent Chrome from displaying warnings, we have now moved everything to HTTPS. There shouldn't be anything different, except that you see your browser stating that the website is served over a secure connection. Everything automatically redirects, so you don't have to do anything special.
Please let me know if you find something which doesn't work anymore.