Bug 36072: opac-request-article should check syspref

Bug 36072: opac-request-article should check syspref

Note: This is handled now just like opac-reserve.

Test plan:
Disable ArticleRequests and hit the page.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
(cherry picked from commit 8afcbe0bbb556cb19ff2e33e56cf3bcb8dd13d11)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>
(cherry picked from commit c4d348651192eaed83d13df4f7d166b977690e6d)
Signed-off-by: Frédéric Demians <f.demians@tamil.fr>