luci.mk: disable english translation packages
luci.mk: disable english translation packages

Since english is the implementation language of LuCI, it makes no sense to
ship translation packages for it.

Ref: #5860
Signed-off-by: Jo-Philipp Wich <bd73d35759d75cc215150d1bbc94f1b1078bee01@mein.io>

openwrt/luci,hnyman/luci,hnyman/luci,hnyman/luci,openwrt/luci,openwrt/luci,hnyman/luci,openwrt/luci,openwrt/luci,hnyman/luci,openwrt/luci,hnyman/luci,hnyman/luci,hnyman/luci,openwrt/luci,openwrt/luci