build: do use AM_GNU_GETTEXT's "need-formatstring-macros" option

* configure.ac: Revert commit 49741b61 and add a comment.
Reported by Eric Blake.

diff --git a/configure.ac b/configure.ac
index 8f019b6..a6d2310 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -429,7 +429,9 @@ CONFIG_STATUS_DEPENDENCIES='$(top_srcdir)/src/Makefile.am'
 AC_SUBST([CONFIG_STATUS_DEPENDENCIES])
 ############################################################################
 
-AM_GNU_GETTEXT([external], [need-ngettext])
+# As long as "grep 'PRI[diouxX]' po/*.pot" reports matches in
+# translatable strings, we must use need-formatstring-macros here.
+AM_GNU_GETTEXT([external], [need-formatstring-macros])
 AM_GNU_GETTEXT_VERSION([0.17])
 
 # For a test of uniq: it uses the $LOCALE_FR envvar.