#1 Crash when placing tower in disallowed location

AsyncErr: Lua: Runtime error from mod 'kobo' in callback item_OnPlace(): ...etest.Minetest/.minetest/games/kobo/mods/kobo/towers.lua:63: bad argument #1 to 'chat_send_player' (string expected, got nil)
stack traceback:
    [C]: in function 'chat_send_player'
    ...etest.Minetest/.minetest/games/kobo/mods/kobo/towers.lua:63: in function 'after_place_node'
    /app/share/luanti/builtin/game/item.lua:303: in function </app/share/luanti/builtin/game/item.lua:144>

fixed.

fixed.