Bug 14579: 'You are not logged in' should link to log in page

Bug 14579: 'You are not logged in' should link to log in page

To test:
1) Go to any page on the staff client and make sure you are not logged in (ie an error page, cgi-bin/koha/errors/400.pl)
2) Try click on 'You are not logged in |'
3) Notice it is not really a link and doesn't take you anywhere
4) Apply patch
5) Refresh page
6) Click on what now says 'Log in |'
7) Confirm that you are redirected to the intranet log in page

Signed-off-by: Aleisha <aleishaamohia@hotmail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>