message: fixed clippy warning "needless  in doctest"
diff: //! assert_eq!(decrypted, plaintext);
  //! # Ok(())
  //! # }
  -//! # fn main() { run_main().unwrap(); }
  +//!
  +//! # run_main().unwrap();
  //! ```
  //!
  //! ## Passphrase-based encryption
  //! assert_eq!(decrypted, plaintext);
  //! # Ok(())
  //! # }
  -//! # fn main() { run_main().unwrap(); }
  +//! # run_main().unwrap();
  //! ```
  // Catch documentation errors caused by code changes.
  