fix: use Rustls NoCertificateVerification for underscore domains instead of AcceptInvalidCertificates

Remove AcceptInvalidCertificates overrides in configure.rs and qr.rs that
caused a fallback to OpenSSL/native-tls. The upstream Rustls TLS layer now
handles underscore-prefixed domains via NoCertificateVerification directly.
Also fix clippy lint in peer_channels.rs (map_or -> is_some_and).

deltachat-rpc-client/src/deltachat_rpc_client/pytestplugin.py

@@ -358,4 +358,3 @@ def remote_bob_loop(channel):
             except Exception:
                 # some unserializable result
                 channel.send(None)
-