attr: disable gettext for host variant

Otherwise it leads to build failure and we don't need it. Fixes:
http://autobuild.buildroot.net/results/59e/59e7e1db122523b292d34405df6dca9faa616da2/



Signed-off-by: Gustavo Zacarias <gustavo.zacarias@free-electrons.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>