Bug 13676: Fixing the OpacSuppression description

Bug 13676: Fixing the OpacSuppression description

To Test
1/ Search for OpacSuppression system preference
2/ Notice that it says "Items marked as suppressed from OPAC search
results
3/ Noticre also that addresses is spelt wrong
4/ Apply patch
5/ Refresh the page, notice addresses is fixed and items has become
biblios

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>