Allocation: Approve button deletes description text

[dsajdak]

When an admin adds text into the description box on the allocation detail page it is wiped out if they click on the 'approve' or the 'deny' button. The 'update' button works as intended.

Task Tests:

1. Sign into ColdFront as the admin user
2. Create a new allocation request
3. Navigate to the allocation requests list and click on the 'Details' button for the pending request
4. Enter a description and click the 'Approve' or 'Deny' button
5. Verify the description text remains and is unchanged.