update DSL client documentation (#1403)

* update DSL client documentation

* Update _client.py

sdk/python/kfp/_client.py

@@ -44,7 +44,9 @@ def __init__(self, host=None, client_id=None):
           service DNS name will be used, which only works if the current environment is a pod
           in the same cluster (such as a Jupyter instance spawned by Kubeflow's
           JupyterHub). If you have a different connection to cluster, such as a kubectl
-          proxy connection, then set it to something like "127.0.0.1:8080/pipeline".
+          proxy connection, then set it to something like "127.0.0.1:8080/pipeline.
+          If you connect to an IAP enabled cluster, set it to
+          https://<your-deployment>.endpoints.<your-project>.cloud.goog/pipeline".
       client_id: The client ID used by Identity-Aware Proxy.
     """