Bug 31877: Fix capitalization: "Delete this Tag" and "Repeat this Tag"

Bug 31877: Fix capitalization: "Delete this Tag" and "Repeat this Tag"

To get to the string in the staff interface:
1. In the staff interface, go to Cataloging
2. Click "New record"
3. Hover the mouse cursor over one of the delete tag buttons (rectangle with a small x next to the tag title)
   --> a little popup thing (tooltip?) appears with "Delete this Tag"
4. Open the developper tools inspector in your browser
5. Click on the delete tag button
   --> the image alt text is "Delete this Tag"
6. Repeat the same check in the authorities editor
7. Apply patch
8. All tooltips and alt text should read correctly now

Signed-off-by: Caroline Cyr La Rose <caroline.cyr-la-rose@inlibro.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>