message: Use chain() for generating bad data
diff: @@ -206,7 +206,7 @@ mod tests {
  .unwrap());
  // Wrong message fails
  - let bad_message_hash = Sha256::digest([MSG, "\0"].concat().as_bytes());
  + let bad_message_hash = Sha256::new().chain(MSG).chain("\0").finalize();
  assert!(!secp256k1_verify(
  &bad_message_hash,
  signature.as_bytes(),
  