Accessing CDN Using Https From A Website Running In Http

I am developing a website which is going to be in http. I was trying to include jquery from google cdn. The answer given here says using protocol-relative URL lets you easily avo

Solution 1:

It's fairly common to do local development in an environment without HTTPS. Using the protocol-relative URL means you can develop on HTTP and not have to worry about remembering to switch it to HTTPS every time you deploy to production.

For CDNs, though, you can be assured the CDN has HTTPS whether you're working locally or in production, so it's entirely fine to hard-code the HTTPS URL there.