Changing disk mounts from webui prevents disk rotation on Atari

[mozzwald]

Steps to reproduce:

1. Mount DOS disk to slot 1, all other slots empty
2. Boot to DOS
3. Mount disk to slot 2 and 3 from webui
4. press disk rotate button (button A) and disks are not rotated

The file handles are reset when mounting from webui and not recreated in populate_slots_from_config() and the disk rotate function checks for file handles being null.

This attempt at recreating the file handle sometimes worked, but not always and I'm not sure why. Maybe there's another way to do it.

void sioFuji::_populate_slots_from_config()
{
    char flag[3] = {'r', 0, 0};

    for (int i = 0; i < MAX_HOSTS; i++)
    {
        if (Config.get_host_type(i) == fnConfig::host_types::HOSTTYPE_INVALID)
            _fnHosts[i].set_hostname("");
        else
            _fnHosts[i].set_hostname(Config.get_host_name(i).c_str());
    }

    for (int i = 0; i < MAX_DISK_DEVICES; i++)
    {
        _fnDisks[i].reset();

        if (Config.get_mount_host_slot(i) != HOST_SLOT_INVALID)
        {
            if (Config.get_mount_host_slot(i) >= 0 && Config.get_mount_host_slot(i) <= MAX_HOSTS)
            {
                strlcpy(_fnDisks[i].filename,
                        Config.get_mount_path(i).c_str(), sizeof(fujiDisk::filename));
                _fnDisks[i].host_slot = Config.get_mount_host_slot(i);
                if (Config.get_mount_mode(i) == fnConfig::mount_modes::MOUNTMODE_WRITE)
                {
                    _fnDisks[i].access_mode = DISK_ACCESS_MODE_WRITE;
                    flag[1] = '+';
                }
                else
                    _fnDisks[i].access_mode = DISK_ACCESS_MODE_READ;

                // Open the file
               _fnDisks[i].fileh = _fnHosts[Config.get_mount_host_slot(i)].file_open(_fnDisks[i].filename, _fnDisks[i].filename, sizeof(_fnDisks[i].filename), flag);
            }
            else
                Debug_printf("populate_slots_from_config: slot %d out of range\n", i);
        }
        else
            Debug_printf("populate_slots_from_config: invalid host slot %d\n", i);
    }
}