OSIS-2666 Display egy not empty warning on some mini trainings
OSIS-2666 Display egy not empty warning on some mini trainings

	modified:   base/business/group_element_years/postponement.py

uclouvain/OSIS-Louvain,uclouvain/osis,uclouvain/osis,uclouvain/osis,uclouvain/OSIS-Louvain,uclouvain/osis,uclouvain/OSIS-Louvain