Bug 38283: fixed wrong ending tag in patron search modal

Bug 38283: fixed wrong ending tag in patron search modal

Fixed mis-matched a/button tags on "Close" button.

To test:
- Apply patch
- In staff interface: Go to acquisitions > suggestions
- Create a new suggestion
- Click on "Set to patron"
- Verify the close button in the modal looks correct and works

Signed-off-by: Jan Steinberg <jan.steinberg@gesis.org>
Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>