Bug 17904: Fix possible SQL injection in late orders

Bug 17904: Fix possible SQL injection in late orders

To recreate:
/cgi-bin/koha/acqui/lateorders.plop=send_alert&ordernumber=1)and%20(select*from(select(sleep(20)))a)--%20&letter_code=0

Notice the delay.

The SQL query is not constructed correctly, placeholders must be used.

This vulnerability has been reported by MDSec.

Signed-off-by: Mirko Tietgen <mirko@abunchofthings.net>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>