Bug 15719: Silence warning in C4/Language.pm during web install - tests

Bug 15719: Silence warning in C4/Language.pm during web install - tests

Test empty database case.

TEST PLAN
---------
1) prove -v t/Languages.t
   -- success (because test case is missing)
2) Apply this patch
3) prove -v t/Languages.t
   -- success, but warning printed.
4) run koha qa test tools

Signed-off-by: Hector Castro <hector.hecaxmmx@gmail.com>
Works as advertised. QA test tools rus OK

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Brendan Gallagher brendan@bywatersolutions.com
(cherry picked from commit 701f427587daa4530041014fae8bf3674351283c)
Signed-off-by: Julian Maurice <julian.maurice@biblibre.com>