fix crash in battery mod (missing meta check)

Vanessa Ezekowitz

2017-04-11 3f8478086db8720c0f4b5066779a55a2d0271260

fix crash in battery mod (missing meta check)

 technic/machines/register/battery_box.lua

@@ -253,6 +253,7 @@
            after_place_node = data.tube and pipeworks.after_place,
            after_dig_node = technic.machine_after_dig_node,
            on_receive_fields = function(pos, formname, fields, sender)
                local meta = minetest.get_meta(pos)
                local nodename = minetest.get_node(pos).name
                if fields.edit_channel then
                    minetest.show_formspec(sender:get_player_name(),