Fixes the following issue: https://github.com/nextcloud/deck/issues/5136
By fixing the following error when running 'php occ deck:import --system=TrelloJson'
Error: Call to a member function getUID() on string in /home/sites/site100028002/web/nextcloud.enklaave.org/apps/deck/lib/Service/Importer/Systems/TrelloJsonService.php:136
and
Error: Call to a member function getUID() on string in /home/sites/site100028002/web/nextcloud.enklaave.org/apps/deck/lib/Service/Importer/Systems/TrelloJsonService.php:364
Signed-off-by: mulles <com.github@emu.lu>
c2425f3c33