Bug 20249: (bug 18789 follow-up) "Patron has no outstanding fines" now appears alongs...

Bug 20249: (bug 18789 follow-up) "Patron has no outstanding fines" now appears alongside fines

Test plan:
    1) Choose two patrons from your database, one who has fines, and the other who does not
    2) Visit their 'Fines' page, and click on the 'Pay fines' tab
        2.1) If they don't have any fines, you'll only see a blank row
        2.2) If they do have fines, the payment form will appear, but the text "... no outstanding fines" will also appear
    3) Apply patch
    4) Visit once again the 'Pay fines' tab of your patrons
        4.1) Now, "... no outstanding fines" will appear for the right situation

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>