Bug 27713: Duplicate search field IDs in MARC framework administration template

Bug 27713: Duplicate search field IDs in MARC framework administration template

This patch makes a minor change to the MARC framework administration
template so that the ID of a form field on the page isn't a duplicate of
one in the header search form.

To test, apply the patch and go to Administration -> MARC bibliographic
framework -> MARC structure.

- Test the "Search for tag" form field to confirm that it works
  correctly.
- Validate the HTML of the page to confirm that there are no "Duplicate
  ID" errors.

Signed-off-by: Phil Ringnalda <phil@chetcolibrary.org>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>