Bug 19392: Clean-up behind auth_values_input_www.t

Bug 19392: Clean-up behind auth_values_input_www.t

The two categories created by this test script are not removed

Test plan:
without this patch, the two authorised value categories 学協会μμ and
tòmas are not removed when the script finishes.
Now it does!

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
(cherry picked from commit 269c21d984ef451dadcad2e803035cc1cd052825)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>
(cherry picked from commit 354645ef3005ca41d832aea8548944f6f2366089)
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>