Bug 10285: Remove links from the error pages

Bug 10285: Remove links from the error pages

The error page (400, 401, 402, 403, 404, 405 and 500) displays parts the old
staff client main page.

The user can easily browses using navigation links.

Test plan:
Go on the 400.pl, 401.pl, 402.pl, 403.pl, 404.pl, 405.pl and 500.pl
pages, and confirm all is fine and you don't get the old style blocks.

Signed-off-by: Nick Clemens <nick@quecheelibrary.org>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
http://bugs.koha-community.org/show_bug.cgi?id=10258
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>