Bug 26703: (follow-up) corrected currencies title

Bug 26703: (follow-up) corrected currencies title

Corrected the page title in the admin/currency file.

To test:
1) Go to staff client
2) Go to admin/currency
3) Check that the page title is "Currencies > Currencies & Exchange rates > Administration > Koha"
4) Check that when adding a currency, the page title is "New currency > Currencies & Exchange rates > Administration > Koha"
5) Check that when modifying a currency, the page title is "Modify currency '[Currency name]' > Currencies & Exchange rates > Administration > Koha"
6) Check that when deleting a currency, the page title is "Confirm deletion of currency '[Currency name]' > Currencies & Exchange rates > Administration > Koha"

Sponsored-by: Catalyst IT
Signed-off-by: Henry Bolshaw <bolshawh@parliament.uk>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>