Fix VD-1301 and VD-1302 vulnerabilities

This patch was contributed by Maor Vermucht and Or Peles from
VDOO Connected Trust.
modbus_mapping_t* modbus_mapping_new(int nb_bits, int nb_input_bits,
                                     int nb_registers, int nb_input_registers)
{
    return modbus_mapping_new_start_address(
        0, nb_bits, 0, nb_input_bits, 0, nb_registers, 0, nb_input_registers);
}

modbus_mapping_t* modbus_mapping_new(int nb_bits, int nb_input_bits,
                                     int nb_registers, int nb_input_registers)
{
    return modbus_mapping_new_start_address(
        0, nb_bits, 0, nb_input_bits, 0, nb_registers, 0, nb_input_registers);
}
