Bug 37260: Check message broker for both 'about' and 'sysinfo' tabs

Bug 37260: Check message broker for both 'about' and 'sysinfo' tabs

Test plan:
1) Apply test patch only
2) Visit <staff_url>/cgi-bin/koha/about.pl
3) Notice it shows 'Using RabbitMQ' (it should show 'Using SQL polling')
4) Apply this patch, repeat 3)
5) Notice it now shows 'Using SQL polling'
6) Remove test patch. Notice it shows 'Using RabbitMQ' again.
7) Repeat test plan but for /cgi-bin/koha/about.pl?tab=sysinfo tab

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Emily Lamancusa <emily.lamancusa@montgomerycountymd.gov>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
(cherry picked from commit 6a321c6ee44413e1e3601d1d9fcd727788e2bb3f)
Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>