Fixed test-utf8-body to actually contain the UTF-8 character

Fixed test-utf8-body to actually contain the UTF-8 character
instead of the single byte, 8-bit character.  This was caught
using Heirloom shell with a UTF-8 locale:  when it wrote the
test draft from a here document, it converted the single byte
character to UTF-8.  This verifies that behavior:

LANG=en_US.utf-8 /usr/lib/heirloom/5bin/sh -c "od -x <<EOF
`printf '\xA1'`
EOF
"