Bug 19034: XSS Flaws in Z39.50/SRU servers administration

Bug 19034: XSS Flaws in Z39.50/SRU servers administration

1. Hit /cgi-bin/koha/admin/z3950servers.pl
2. Enter <IFRAME SRC="javascript:alert('XSS');"></IFRAME> search Z39.50/SRU servers box.
3. Notice the iframe is executed.
4. Apply patch.
5. Reload page, and enter iframe again on search Z39.50/SRU servers box.
6. Notice it is no longer executed.

Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
(cherry picked from commit cd0c7ad870f4c2d202e2d6e31c1078bd29da979e)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>