The gap in security your browser is pointing out is common on most sites, but Google,firefox,IE has decided to start highlighting it now. It's telling you that the site is vulnerable to a MIM attack (or Man in the Middle), where someone intercepts what you are typing on the site. Since everything you type here is view-able to all, this has never been a thing it made sense to protect against. As long as you aren't typing your password into a thread in plain text, or your bank info, this doesn't affect you.
All that said, we are going to be upgrade all our network over the coming months to HTTPS to make our pages secure.