Bug 16675: fix breakage of t/Languages.t

Bug 16675: fix breakage of t/Languages.t

This patch fixes test breakage introduced by the patch for bug 16088,
which added caching of getlanguages().  Upon inspection, it looks like
the patch for 16088 does not introduce a regression on bug 10560,
so this patch adds a couple cache-clearings.

To test
-------
[1] Verify that t/Languages.t passes.

Signed-off-by: Galen Charlton <gmcharlt@gmail.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
(cherry picked from commit b9b4eeb849dcb52053a98440e1d8fb02011a9005)
Signed-off-by: Frédéric Demians <f.demians@tamil.fr>