Bug 19371: Changed table column text to 'Cancel?' on the patron circulation page

Bug 19371: Changed table column text to 'Cancel?' on the patron circulation page

Test plan:
1. Place a hold on an item

2. Search for the patron who the hold is associated with

3. View the Hold(s) tab of the Checkouts page and notice there is a
column with the text 'Delete?' and a button below the table with the
text 'Cancel marked holds'

4. Apply patch

5. Notice that the column text described in step 3 now has the text
'Cancel?' and the button text is the same as it was in step 3

Sponsored-By: Catalyst IT
Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>