This is a side-effect of us using JavaScript APIs instead of Python TLS and setting `is_verified` on the `EmscriptenHTTPConnection` so urllib3 is emitting an `InsecureRequestWarning` for every request, even ones that are using HTTPS. * Set the proper value of `is_verified` depending on whether the request is HTTP or HTTPS. * Add a test case that asserts that an `InsecureRequestWarning` is emitted for HTTP and isn't emitted for HTTPS.