Bug 26530: Use patron card number as checkbox label during patron merge

Bug 26530: Use patron card number as checkbox label during patron merge

This patch makes a minor change the the merge patrons template so that
on the patron selection stage the user can click the card number to
select the radio button.

To test, apply the patch and perform a patron search in the patrons
module.

- In patron search results, select two patrons to merge.
- Click the "Merge selected patrons" button.
- On the page showing the two patrons to merge, click each of the card
  numbers to confirm that it selects the correct radio button.

Signed-off-by: Jennifer <jennifer.marlatt@coronaca.gov>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>