Bug 31425: Minor correction to patron categories admin title

Bug 31425: Minor correction to patron categories admin title

This patch corrects the patron categories administration template so
that an extra angle bracket isn't included in the page title on the main
view.

To test, apply the patch and go to Administration -> Patron categories.
The page title should read:

Patron categories › Administration › Koha

...with no extra "›" at the beginning.

Check that other views (new, edit, delete) are unaffected.

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>