Fix MSRV in readme

opaque-debug/README.md

@@ -29,7 +29,7 @@ Unless you explicitly state otherwise, any contribution intentionally submitted
 [docs-image]: https://docs.rs/opaque-debug/badge.svg
 [docs-link]: https://docs.rs/opaque-debug/
 [license-image]: https://img.shields.io/badge/license-Apache2.0/MIT-blue.svg
-[rustc-image]: https://img.shields.io/badge/rustc-1.65+-blue.svg
+[rustc-image]: https://img.shields.io/badge/rustc-1.41+-blue.svg
 [chat-image]: https://img.shields.io/badge/zulip-join_chat-blue.svg
 [chat-link]: https://rustcrypto.zulipchat.com/#narrow/stream/260052-utils
 [build-image]: https://github.com/RustCrypto/utils/workflows/opaque-debug/badge.svg?branch=master&event=push