IT gh#813

#813 hide packing instruction and qty when null

Testcase to check if the none are displayed when the packing instruction and qty are null.

1. Create 2 sales order for G000X:
   • 1st: P0001, 2 TU A and P0002, 5 TU B
   • 2nd: P0001, don’t select TU (=> Virtual PI in orderline)
2. Complete both and check the jaspers:
   • => 1st has headers “Anzahl” and “Packvorschrift” displayed, with 2 TU A and 5 TU B
   • => 2nd has no “Anzahl” and “Packvorschrift” since no PI was used in the order (just “Menge” is displayed, for the qty of product)