Bug 18700 Fix grammar (data cannot be pluralized)

Bug 18700 Fix grammar (data cannot be pluralized)

data is a mass noun or plural of datum - datas is ungrammatical
and jarring for a native speaker.
Split the awkward sounding sentence into two for more clarity,
thanks to Marc Véron for the suggestion.

Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
(cherry picked from commit 60b31a7a2219dea16f124684bd21e6d12a35c05a)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>