Comment 2 for bug 1485020

I like that Firefox tells you about this, but I don't think this should be a non-overrideable error. This type of error should fall into the same bucket as self-signed certificates: "Hey, we don't trust this because of X. Are you sure you want to continue?"

I think that would be a decent fix for this without A) disabling this feature all together or B) making Firefox figure out if its behind a captive portal. I don't know if that would be a config change or a code change, though. Thoughts?