This release contains a few fixes regarding cancellation of operations, and an experimental feature to use DNS over HTTPS (DoH) in Origin requests. Features: - Experimental support for resolving names using DNS over HTTPS (DoH) for the Origin request mechanism. To enable it, you must provide the client with an `--origin-doh-base` option and give it a DoH base URL argument (like `https://mozilla.cloudflare-dns.com/dns-query` as used by Mozilla, more options [here](https://github.com/curl/curl/wiki/DNS-over-HTTPS)). DoH requests are handled internally as normal requests (respecting public/private browsing mode), and responses may be shared to the distributed cache. The feature is still slow since no private caching is used, so each requested URL triggers a full DoH request. Bugfixes: - Fix checks for cancellation in several places (SSL client handshake, session flush, timeouts, fresh injection). - Check for errors after performing `CONNECT` to Proxy. - Fix case comparison of `X-Ouinet-Private` header values.