Bug 30703: Remove a few CookieManager warnings

Bug 30703: Remove a few CookieManager warnings

Running Auth.t produces several warnings like:
Use of uninitialized value $name in hash element at /usr/share/koha/Koha/CookieManager.pm line 103.
Use of uninitialized value $name in hash element at /usr/share/koha/Koha/CookieManager.pm line 104.
Use of uninitialized value $name in hash element at /usr/share/koha/Koha/CookieManager.pm line 112.
Use of uninitialized value $name in hash element at /usr/share/koha/Koha/CookieManager.pm line 103.
Use of uninitialized value $name in hash element at /usr/share/koha/Koha/CookieManager.pm line 104.
Use of uninitialized value $name in hash element at /usr/share/koha/Koha/CookieManager.pm line 112.
Use of uninitialized value $name in hash element at /usr/share/koha/Koha/CookieManager.pm line 103.
Use of uninitialized value $name in hash element at /usr/share/koha/Koha/CookieManager.pm line 104.
Use of uninitialized value $name in hash element at /usr/share/koha/Koha/CookieManager.pm line 112.

Test plan:
prove  t/CookieManager.t t/db_dependent/Auth.t

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>