CI failure with specific bitreq features

[jamillambert]

I just got a CI failure unrelated to the PR. I checked and it also fails on master:

cargo --locked test --no-default-features "--features=async-https-native-tls base64 https-native-tls log proxy rustls rustls-native-certs rustls-webpki serde std tokio-rustls"

Fails with:

test test_https ... FAILED

failures:

---- test_https stdout ----

thread 'test_https' (1674728) panicked at bitreq/tests/setup.rs:280:17:
assertion `left == right` failed
  left: "IoError(Custom { kind: InvalidData, error: InvalidCertificate(UnknownIssuer) })"
 right: "HttpsFeatureNotEnabled"
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace