Bug 17993 - Do not use modal authentication with CAS - tags bis

Bug 17993 - Do not use modal authentication with CAS - tags bis

Bug 12046 corrected the fact that modal dialog does not allow to use the
CAS authentication in main authentication link. This must also be
corrected in link for tags in detail tags page: "Log in to see your own
saved tags."

Test plan :
- Enable syspref casAuthentication
- Go to OPAC, not authenticated
- Click on "Tag cloud"
- Click on "Log in to see your own saved tags"
=> Without patch you get the modal login popup
=> With patch you go to the login page opac-user.pl

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Mason James <mtj@kohaaloha.com>