Bug 23253: (bug 22318 follow-up) Fix OpacNavRight even if opacuserlogin is off

Bug 23253: (bug 22318 follow-up) Fix OpacNavRight even if opacuserlogin is off

There are other occurrences of OpavNavRight that bug 22318 forgot to
adjust to use the news system instead of the syspref.

Test plan:
- turn off opacuserlogin
- create a news for OpacNavRight
- go to the opac main page
=> Confirm that the OpacNavRight content is displayed correctly.

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
(cherry picked from commit ee7ba48bfe9d3f43bbc1bb88f62bf12854e5a838)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>