Bug 14467: Security updates break some Koha plugins

Bug 14467: Security updates break some Koha plugins

The new security updates break previously functioning plugins, most
notably the cover flow plugin and the Ebsco EDS plugin.

Test Plan:
1) Install and configure the cover flow plugin ( http://bywatersolutions.com/koha-plugins/ )
2) Note that attempting to access coverflow.pl from the OPAC results in an error
3) Apply this patch
4) Note that coverflow.pl now output html again

Signed-off-by: Nick Clemens <nick@quecheelibrary.org>
Signed-off-by: Jonathan Druart <jonathan.druart@koha-community.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@unc.edu.ar>