Bug 19611: Fix XSS Flaws in supplier.pl

Bug 19611: Fix XSS Flaws in supplier.pl

Test
1. Hit the page /cgi-bin/koha/acqui/supplier.pl?op=enter
2. Add a text in the field Name that contains java script
3. Save the page.
4. Notice js is execute
5. Apply patch and reload the js is escaped

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>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
(cherry picked from commit 99d327a5ea039b98f2bb19a3ef29431b33437cb7)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>