dnsmasq: fix build without NLS

dnsmasq i18n support requires NLS for the provided gettext utilities.
Locale support, OTOH, is not required.

Fixes:
http://autobuild.buildroot.net/results/d45/d453aff1ce1f5e1d380bd7692a4a0565505027a3/
http://autobuild.buildroot.net/results/fb7/fb7844a239472eb48c18778aa7d515552ccfb4b9/
http://autobuild.buildroot.net/results/d85/d856ec3e6b28bd723176bb892a56dff5262a6b92/



Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>