add permision to all

JoinTheCityREST/app/Discussion/models.py

@@ -23,7 +23,7 @@ class Discussion(models.Model):
     def __str__(self):
         return self.question
 
-    def add_message(self, user, text):
+    def add_message(self, user, text=""):
         message = TextMessage.objects.create(user=user, text=text)
         message.save()
         self.message.add(message)