Bug 34083: (follow-up) Prevent showing 'null'

Bug 34083: (follow-up) Prevent showing 'null'

In patron lists, if the patron added is an organization without the firstname, it presents 'null'. This fixes that

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
(cherry picked from commit 17e19fe311d470e73d2cca332ffcce4dc5663a47)
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
(cherry picked from commit fd372ddcd3153b8e7027e2f4a223c62ceae46dc0)
Signed-off-by: Pedro Amorim <pedro.amorim@ptfs-europe.com>