Bug 13400: Untranslatable "Are you sure you want to delete this authority?"

Bug 13400: Untranslatable "Are you sure you want to delete this authority?"

This patch makes the string "Are you sure you want to delete this
authority?" translatable using the function _(...)

To test, apply patch and check that deleting authorities still works.

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Tested successfully with the following procedure:

1. Applied the patch.
2. Ran perl translate update de-DE
3. Edited de-DE-i-staff-t-prog-v-3006000.po to add a "translation"
4. Removed "#, fuzzy" marker from po entry.
5. perl translate -v install de-DE
6. Testing deleting an authority from the authority search results page
   and from the detail page. My translated string appeared correctly.

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>