Customers hoping to purchase the iPhone 5 through Apple’s website will now have to wait three to four weeks for shipment, as high demand for the phone continues to absorb supplies. This follows Apple’s official announcement that iPhone 5 pre-orders exceeded 2 million in the first 24 hours of sale. Customers who haven’t pre-ordered and still want the phone by its Sept. 21 release date will likely have to wait in line for Apple’s…