fix build

misago/threads/threadtypes/thread.py

@@ -45,7 +45,7 @@ class Thread(ThreadType):
         )
 
     def get_category_read_api_url(self, category):
-        return '{,}?category={,}'.format(reverse('misago:api:thread-read'), category.pk)
+        return '{}?category={}'.format(reverse('misago:api:thread-read'), category.pk)
 
     def get_thread_absolute_url(self, thread, page=1):
         if page > 1: