Bug 14436: Noisy warns in C4/Utils/DataTables/Members.pm

Bug 14436: Noisy warns in C4/Utils/DataTables/Members.pm

TEST PLAN
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1) Backup the koha intranet error log.
2) Empty the koha intranet error log.
3) In staff client, go to Patrons
   (/cgi-bin/koha/members/members-home.pl)
4) Pick any letter to 'Browse by last name'
   -- koha intranet error log now has warns.
   -- the one of importance is the uninitalized value.
5) Empty the koha intranet error log.
6) apply this patch
7) Repeat steps 3 & 4.
   -- koha intranet error log does not contain the
      uninitialized value error.
8) run koha qa test tools.

Signed-off-by: Indranil Das Gupta (L2C2 Technologies) <indradg@gmail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@unc.edu.ar>