UI console: Restore tty settings, do not force ECHO after prompt

The Console UI method always set echo on after prompting without
echo.  However, echo might not have been on originally, so just
restore the original TTY settings.

Fixes #2373

Reviewed-by: Andy Polyakov <appro@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6157)