Bug 13270: Don't display "vendor note" label if nothing to display

Bug 13270: Don't display "vendor note" label if nothing to display

Bug 12111 removes the vendor note edition on receiving.
The label should not be displayed when it's empty.

Test plan:
1/ Receive an order without a vendor note and verify that the label is not
displayed.
2/ Receive an order with a vendor note and verify that the note is
displayed.

Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Works as described, small template change.