olpc-update slow in recent builds

[Tomeu Vizoso]

Hi all,

just discovered (well, Michael told me), that the -f switch is needed so
olpc-update is as fast as it has been until recent images.

Looks like by default, olpc-update will try to be gentle with the
network and cpu so it upgrades quite (very) slowly.

Thought it would be worth telling here as I was quite a bit frustrated
after trying to update to joyride from update1.

Regards,

Tomeu