Fix discussions by correctly serializing outgoing course_ids

lms/lib/comment_client/user.py

@@ -87,7 +87,7 @@ class User(models.Model):
         if not self.course_id:
             raise CommentClientRequestError("Must provide course_id when retrieving active threads for the user")
         url = _url_for_user_active_threads(self.id)
-        params = {'course_id': self.course_id}
+        params = {'course_id': self.course_id.to_deprecated_string()}
         params = merge_dict(params, query_params)
         response = perform_request(
             'get',
@@ -103,7 +103,7 @@ class User(models.Model):
         if not self.course_id:
             raise CommentClientRequestError("Must provide course_id when retrieving subscribed threads for the user")
         url = _url_for_user_subscribed_threads(self.id)
-        params = {'course_id': self.course_id}
+        params = {'course_id': self.course_id.to_deprecated_string()}
         params = merge_dict(params, query_params)
         response = perform_request(
             'get',
@@ -119,7 +119,7 @@ class User(models.Model):
         url = self.url(action='get', params=self.attributes)
         retrieve_params = self.default_retrieve_params
         if self.attributes.get('course_id'):
-            retrieve_params['course_id'] = self.course_id
+            retrieve_params['course_id'] = self.course_id.to_deprecated_string()
         try:
             response = perform_request(
                 'get',