Bug 14683: [QA Follow-up] Similar change for staff

Bug 14683: [QA Follow-up] Similar change for staff

Script memberentry.pl contained a similar line.
Solution is simpler here.

Test plan:
[1] Add, change or clear the sms number at staff side.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
(cherry picked from commit bdf4894c507f4bac6b2b79c7ca3b7a556d246ed5)
Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>
(cherry picked from commit c323e07c0c7ec403af15e40da7d82b997cb3eefc)
Signed-off-by: Liz Rea <wizzyrea@gmail.com>