fix the polymorphic bug

Author: alex.chen

modules/swagger-codegen/src/main/resources/python/api_client.mustache

@@ -608,8 +608,7 @@ class ApiClient(object):
         :return: model object.
         """
 
-        if not klass.swagger_types and not self.__hasattr(klass,
-                                                   'get_real_child_model'):
+        if not klass.swagger_types and not self.__hasattr(klass, 'get_real_child_model'):
             return data
 
         kwargs = {}