Bug 20023: (QA follow-up) Tiny simplification

Bug 20023: (QA follow-up) Tiny simplification

Remove empty emails from the list rightaway.
Would be tempted to lc the params->{email} at the start btw..

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
(cherry picked from commit eec74a2cd1847a859b4fab37c42882ba192ee560)
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
(cherry picked from commit c5bb4d6529f9dcd2457639c8b7735dfc7001d244)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>