build: add variable to restrict po language and use it for the core i18n packages
[project/luci.git] / i18n /
drwxr-xr-x   ..
drwxr-xr-x - english
drwxr-xr-x - french
drwxr-xr-x - german
drwxr-xr-x - greek
drwxr-xr-x - italian
drwxr-xr-x - japanese
drwxr-xr-x - portuguese_brazilian
drwxr-xr-x - russian