Bug 19086: Fix Stored XSS in supplier.pl

Bug 19086: Fix Stored XSS in supplier.pl

1. Hit the page /cgi-bin/koha/acqui/supplier.pl?op=enter
2. Add a text in the field company_postal, physical, company_fax,
   accountnumber, contactposition, contact_fax, contact_notes, notes 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: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>