bug#30405: 26.0.91; Incorrect apostrophe translation in ImageMagick error message

[Noam Postavsky]

Glenn Morris <rgm@gnu.org> writes:

> Present since 25.1. Perhaps a minimal example is:
> emacs -Q
> (set-buffer-multibyte nil)
> (message "can't")

The issue with message producing fancy quotes is new in 25.1, although
stepping with the debugger, it looks like the root cause is that the
" *Echo Area 0*" buffer becomes unibyte along with the main buffer.  So
the following shows the problem in earlier versions as well:

(set-buffer-multibyte nil)
(message "can\u2019t")