Fixed a bug I introduced while making so the user didn't have to make
two extra clicks just to confirm s/he didn't need shipping when no shippable
items are present in the order.
In the current brain dead e-commerce page flow, process-order-quantity-shipping
*must* be called no matter what, because that's the page that actually gives
ec_items prices, and without them the user ends up with a $0 total for his
order, always.
