Don't set notes if there isn't anyone

Signed-off-by: Emmy D'Anello <emmy.danello@animath.fr>

participation/models.py

@@ -1327,6 +1327,8 @@ class Pool(models.Model):
             for i, passage in enumerate(self.passages.all()):
                 note = passage.notes.get(jury=jury)
                 note_line = line[2 + i * passage_width:2 + (i + 1) * passage_width]
+                if not note_line:  # There is no note
+                    continue
                 note.set_all(*note_line)
                 note.save()