Blogspot blogs are banned in Iran, they redirected to a page that says you can't access that site. But when I try to open a blog via HTTPS prefix I get this error:

This is certification detail:

If I click "Procced anyway" it goes to https://www.google.com with green certification icon. (Figure blow)

Question
How to make sure this connection is secure(I'm using a public WiFi)? Because it's so weird that I'm redirecting to a https://www.google.com/ instead of blog or even blocking alert page.