i18n: bisect: simplify error message for i18n
The message was not being extracted by xgettext, although it was marked
for translation, seemingly because it contained a command substitution.
Moreover, eval_gettext should be used instead of gettext for strings
with substitution.
See step 4. of section 15.5.2.1 Preparing Shell Scripts for
Internationalization from gettext manual [1]:
"Simplify translatable strings so that they don't contain command
substitution ("`...`" or "$(...)") [...]"
[1] http://www.gnu.org/software/gettext/manual/html_node/Preparing-Shell-Scripts.html
Signed-off-by: Vasco Almeida <vascomalmeida@sapo.pt>
Signed-off-by: Junio C Hamano <gitster@pobox.com>