EB: Add run_once to database migration tasks
EB: Add run_once to database migration tasks

baszoetekouw/OpenConext-deploy,OpenConext/OpenConext-deploy,baszoetekouw/OpenConext-deploy,baszoetekouw/OpenConext-deploy,OpenConext/OpenConext-deploy,baszoetekouw/OpenConext-deploy,baszoetekouw/OpenConext-deploy,OpenConext/OpenConext-deploy,OpenConext/OpenConext-deploy,OpenConext/OpenConext-deploy