common: Fix fallback handling to utf-8.
* common/utf8conv.c (handle_iconv_error): Set NO_TRANSLATION.
(cherry picked from commit 393dcdd61c3b2da00a97176c647d9bd1c908ceba)
- GnuPG-bug-id: T5038
- Fixes-commit: 99c9bf7defd6c1ac9cc49c84e6c78eeb886a6952
- Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>