Bug: /system routerboard usb excluded from export on LtAP

Hi all,

Small bug I've found in RouterOS 7.1.3 on an LtAP.

When the configuration is set as follows:

/system routerboard usb> set type=mini-PCIe

overriding the default value of type: USB-type-A

This is excluded from the /export command.

This breaks config backups, as the system routerboard usb setting is not restored.

Regards,
Graham