Bug 37823: Remove unreachable code in vendor contract page

Bug 37823: Remove unreachable code in vendor contract page

The vendor contract management page has a few sections of code that are
meant to display a minimal confirmation message ("Data recorded") after
saving a new or edited vendor contract.

However, aqcontract.pl redirects back to the vendor details page after
saving, so this code is never reached and should be removed.

Test plan:
1. Apply patch
2. Go to the Acquisitions module and find a vendor
3. Click + New > Contract
4. Fill in the information and click Save
5. Click the "Contracts" link in the navigation menu on the left
--> Confirm that the contract was saved correctly
6. Click the Edit button and make changes to all fields
7. Save the information and click "Contracts" again
--> Confirm that the new information saved correctly

Signed-off-by: Phil Ringnalda <phil@chetcolibrary.org>
Signed-off-by: Julian Maurice <julian.maurice@biblibre.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>