I'm guessing this is some shared hosting solution where you don't have a lot of control or ability to add things like LetsEncrypt (but I'm sure GoDaddy will sell you their SSL offerings).

I noticed some of my sites getting Vodaphone banners when using Ireland/UK sim cards and realize they were injecting crap into my site. That really helped me make the push to use LetsEncrypt on everything.

I realize that 3rd party Wi-Fi/ISPs injecting code is a slightly different issue that the one in the article, but the solution is running SSL everywhere. If you need to login to a captive portal that redirects, there's always neverssl.com