Add missing protocol to readme.
diff --git a/README.rst b/README.rst
index a1a0d8f..237812c 100644
--- a/README.rst
+++ b/README.rst
@@ -98,6 +98,7 @@
         master:
           host: jenkins.example.com
           port: 80
+          protocol: http
         user:
           name: jenkins_slave
           password: dexiech6AepohthaiHook2iesh7ol5ook4Ov3leid3yek6daid2ooNg3Ee2oKeYo