Allow many contributors in NoteSerializer

program/serializers.py

@@ -653,7 +653,7 @@ class NoteLinkSerializer(serializers.ModelSerializer):
 class NoteSerializer(ThumbnailsMixin, serializers.ModelSerializer):
     links = NoteLinkSerializer(many=True, required=False)
     timeslot = serializers.PrimaryKeyRelatedField(queryset=TimeSlot.objects.all())
-    contributors = serializers.PrimaryKeyRelatedField(queryset=Host.objects.all())
+    contributors = serializers.PrimaryKeyRelatedField(queryset=Host.objects.all(), many=True)
     thumbnails = serializers.SerializerMethodField()
 
     class Meta: