test-https: add some more known failure messages of client certs (issue6030)
I don't think the exact error message is important here. On Debian sid,
ECONNRESET is raised, and "[SSL] tlsv13 alert certificate required" on NetBSD.
# Rust builds with a modern MSVC and uses a newer CRT.
# Python 2.7 has a shared library dependency on an older CRT (msvcr90.dll).
# We statically link the modern CRT to avoid multiple msvcr*.dll libraries
# being loaded and Python possibly picking up symbols from the newer runtime
# (which would be loaded first).
[target.'cfg(target_os = "windows")']
rustflags = ["-Ctarget-feature=+crt-static"]