[PATCH] configure.ac: crank up gettext version

[Sam James]

Even if newer gettext is installed, the version used & paths taken
are gated on the macro's argument. Older gettext can't handle musl's
libintl situation correctly and end up silently skipping it.

There's also a bunch of modernisation which avoids some warnings
in newer versions. 0.21 is in Debian stable so should be fine.

Signed-off-by: Sam James <sam@gentoo.org>
---
 configure.ac | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index 69b6fca..4966e40 100644
--- a/configure.ac
+++ b/configure.ac
@@ -37,7 +37,7 @@ AC_SYS_LARGEFILE
 AM_PROG_AR
 LT_INIT
 
-AM_GNU_GETTEXT_VERSION([0.18.2])
+AM_GNU_GETTEXT_VERSION([0.21])
 AM_GNU_GETTEXT([external])
 
 AC_ARG_ENABLE([debug],
-- 
2.38.1