If customer address book blank, admin cannot split shipment to 2 addresses

Description

Precondition: Customer address book is blank.

Steps to reproduce:

1. Go to Commerce Manager.
2. Create a new order for a customer who has a blank address book.
3. Add some items, input billing address and shipping address (for example: Address A) => Click OK. A new order is created.
4. In order to split shipment to address A and address B, choose move shipment => "Move Line Item" dialog opens.
5. Select "Create new shipment." There is only address A in Address drop-down list => Click OK => There are 2 shipments to address A.
6. Click on "Edit Shipping Address" of one shipment, change address information to address B => click OK.

Expected Result: 2 shipments, one to address A and one to address B.
Actual Result: 2 shipments, both to address B.