package/shadow: fix NLS build

NLS is an optional dependency since the addition of the package in
commit f78c5cb5cae93a9e63dad4361d78e1787759382f:

/home/autobuild/autobuild/instance-0/output-1/host/lib/gcc/arm-buildroot-linux-musleabi/12.3.0/../../../../arm-buildroot-linux-musleabi/bin/ld: ../lib/.libs/libshadow.a(libshadow_la-alloc.o): in function `xcalloc':
alloc.c:(.text+0x7c): undefined reference to `libintl_gettext'

Fixes: f78c5cb5cae93a9e63dad4361d78e1787759382f
 - http://autobuild.buildroot.org/results/9f604d09745ffa1f4db3bdcfe0326c236effac0c

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit f82384652c0feed99dc07f08fae5ec1646d38dfc)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/shadow/shadow.mk

@@ -10,6 +10,8 @@ SHADOW_SOURCE = shadow-$(SHADOW_VERSION).tar.xz
 SHADOW_LICENSE = BSD-3-Clause
 SHADOW_LICENSE_FILES = COPYING
 SHADOW_CPE_ID_VENDOR = debian
+SHADOW_DEPENDENCIES = $(TARGET_NLS_DEPENDENCIES)
+SHADOW_CONF_ENV = LIBS=$(TARGET_NLS_LIBS)
 
 SHADOW_CONF_OPTS = \
 	--disable-man \