8.0-BETA2 sysinstall ignoring setting of nonInteractive

[David Boyd]

With 8.0-BETA(1/2) sysinstall ignores setting of nonInteractive variable
when using USB-based install.

With or without nonInteractive sysinstall issues message "Using USB device:
da0a" and waits for confirmation.

This breaks unattended installations using USB device.

Thanks.