Bug 12176: [QA Follow-up] Capitalization typo after eleventh hour

Bug 12176: [QA Follow-up] Capitalization typo after eleventh hour

While cleaning up, still found this super tiny string typo :)
Yes, Tag Editor should now be Tag editor.

Test plan :)
Git grep on Tag editor and Tag Editor

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Bernardo Gonzalez Kriegel <bgkriegel@gmail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@koha-community.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>