Bug 37913: Remove more unreachable code in aqcontract.tt

Bug 37913: Remove more unreachable code in aqcontract.tt

When you successfully delete an acquisitions contract, you are redirected to
the page with the vendor details, which shows contracts for that vendor, which
shows you that the contract you deleted was deleted.

The aqcontract.tt template has a block in [% IF ( delete_confirmed ) %] (which
is never set) that thinks it will show you a '<h1>Contract deleted</h1>' and
make you click an OK button. That block has never been shown, but the button
is in a form which POSTs without an 'op' param, which is now forbidden by the
CSRF code, and will be caught by a test once bug 37728 updates the test.

There's nothing visible to test, so the test plan just makes sure nothing
blows up and you can still delete a contract.

1. Nothing will change, so start with the patch applied
2. Acquistions - click the Search button to search for vendors
3. New -> Contract
4. Give it a name, a start date, and an end date, and Save
5. In the list of contracts for My Vendor, click the Delete button for
   the contract you created
6. In the confirmation page asking if you wanted to delete, click 'Yes,
   delete contract'
7. Note that you are at acqui/supplier.pl?booksellerid=1, the details page
   for the vendor, and your contract isn't listed at the bottom of the page,
   and especially that you weren't shown a page that just said "Contract
   deleted."

Sponsored-by: Chetco Community Public Library
Signed-off-by: Sukhmandeep Benipal <sukhmandeep.benipal@inLibro.com>
Signed-off-by: Paul Derscheid <paul.derscheid@lmscloud.de>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>