Bug 16969 cgi->param used in list context in opac-memberentry.pl

Bug 16969 cgi->param used in list context in opac-memberentry.pl

To test
1/ Hit the page, notice the warning in the log
2/ Apply patch
3/ Hit page, notice no warning in the log
4/ Test functionality all still works

Works as expected. (Note: See Bug 16960 for updating patron details).
Signed-off-by: Marc <veron@veron.ch>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
(cherry picked from commit 0ef3b19dbd414539dbc8c45ecc595e399df31781)
Signed-off-by: Frédéric Demians <f.demians@tamil.fr>