package/libvirt: fix NLS build

package/libvirt: fix NLS build

Fix the following build failure raised since the addition of the package
in commit ccfc90e1010e42e6529afae3a5ea8bf7226dabc1:

/tmp/instance-0/output-1/host/opt/ext-toolchain/bin/../lib/gcc/i686-buildroot-linux-uclibc/9.3.0/../../../../i686-buildroot-linux-uclibc/bin/ld: src/util/libvirt_util.a(viralloc.c.o): in function `virInsertElementsN':
viralloc.c:(.text+0x167): undefined reference to `libintl_dgettext'

Fixes:
 - http://autobuild.buildroot.net/results/2349c55a4a42f08ca52700c60cda3065b0c4bd88

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>