OSIS-3124 Fix str format %d with str
OSIS-3124 Fix str format %d with str

	modified:   base/business/learning_units/edition.py

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