Fix account activation expiry calculation
Fix account activation expiry calculation

Previously we were saying the activation key has expired if:

	current_time - expiry_time > 86400

But this actually gives an extra 24 hours for the key to expire. The
correct calculation is actually simpler:

	current_time > expiry_time

Signed-off-by: Andrew Clayton <02e0a999c50b1f88df7a8f5a04e1b76b35ea6a88@opentechlabs.co.uk>

ac000/receiptomatic