Doors: Avoid crash on nil player in 'can dig door'

mods/doors/init.lua

@@ -203,12 +203,7 @@ end

local function can_dig_door(pos, digger)
	replace_old_owner_information(pos)
	if default.can_interact_with_node(digger, pos) then
		return true
	else
		minetest.record_protection_violation(pos, digger:get_player_name())
		return false
	end
	return default.can_interact_with_node(digger, pos)
end

function doors.register(name, def)