Bug 19453: Incorrect jQuery selector for fund drop down validation

Bug 19453: Incorrect jQuery selector for fund drop down validation

Steps to reproduce:
1. Create a new basket
2. Choose "Add to masket"
3. Choose "From a staged file"
4. Select a file
5. Save without selecting a fund

Expected results: A validation error should be shown, and form submit
halted.

Actual results: No validation error is shown and form submits.

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>