Bug 37090: Correct op parameter in edi_accounts.pl

Bug 37090: Correct op parameter in edi_accounts.pl

To test:
1. Go to Acquisitions > EDI Accounts
2. Create an EDI account if one is not already there
3. Try to delete the EDI account
--> Page refreshes and nothing happens
4. Apply patch, restart_all, and refresh the page
5. Try to delete the EDI account again
--> A confirmation page displays with correct information
6. Click "Yes, delete"
--> The EDI account is deleted

Signed-off-by: Matt Blenkinsop <matt.blenkinsop@ptfs-europe.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>