Piece quantity is not changed, when location is changed in Open order

Overview:
Issue was found in scope of testing UIOR-609
Root cause : Editing the location creates additional pieces. This will be a problem for receiving.

Steps to Reproduce:

Create a POL for P/E mix
Add quantity 1 for both P and E
Save and open PO
See receiving, two expected pieces are created
Edit POL and change location
Save and close POL

Expected Results:
Ideally the piece location is updated for any piece that is still "Expected" and at very least additional pieces are NOT created unless the quantity is changed.

Actual Results:
See receiving now has 4 "Expected" pieces but quantity did not change.