Bug 25862: Prevent TinyMCE to mangle local url links

Bug 25862: Prevent TinyMCE to mangle local url links

To test:
1 create a report 1 if it doesn't exist
2 open /cgi-bin/koha/tools/koha-news.pl
3 create a news
4 add a HTML link with Insert/Edit link tinyMCE dialog box to
  /cgi-bin/koha/reports/guided_reports.pl?reports=1&phase=Run%20this%20report "report 1"
5 save
6 on the main page "report 1" link returns a 404 error

Apply patch
7 Modify news' URL
8 Test it works in: tools/koha-new.pl admin/branches.pl and admin/preferences.pl

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>