fix encoding issue (#18055)

concerto_2_chrono_format.py

@@ -140,8 +140,8 @@ class ConcertoFormatter(object):
             agenda_id = event['ID_LIE']
             if not agenda_id in agendas:
                 nursery_slug = agenda_id
-                nursery = event['LIB_NOM_LIE']
-                agenda = {'slug': nursery_slug, 'label': unicode(nursery, errors='replace'),
+                nursery = event['LIB_NOM_LIE'].decode('iso-8859-1').encode('utf8')
+                agenda = {'slug': nursery_slug, 'label': nursery,
                           'events': [], 'kind': 'events', 'minimal_booking_delay': 0, 'maximal_booking_delay': 30}
                 agenda['permissions'] = {'edit': None, 'view': None}
             else: