Bug 9346 - acqui/neworderempty.pl ignores exchange rates and destroys user data on...

Bug 9346 - acqui/neworderempty.pl ignores exchange rates and destroys user data on page load

This restores behaviour of new order form before Bug 5335 merge

Test scenario:

1. load Receipt summary for existing customer
2. take note of Unit cost and Order cost
3. open existing order line and verify that Replacement cost,
   Budgeted cost and Total are not re-calculated on page load
4. change currency and verify that costs are updated
   (change currency to system default and all values should become
   same as vendor price)
5. change Quantity, get alert "You can't add a new item, please create a new order line"
   and verify that Total still reflects correct value

Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Elliott Davis <elliott@bywatersolions.com>
Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>
Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>