Bug 20689: (follow-up) Correct scope of template variables

Bug 20689: (follow-up) Correct scope of template variables

The removal of the <select>s should have been accompanied by a
correction to the scope of tagfield and tagsubfield. It is also
unnecessary to conditionally include the "value" attribute.

To test, apply the patch and test the process for editing an item search
field. All the correct values should appear in form fields during edit,
and all values should save correctly.

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>