Bump jenkins image version

Change-Id: Ifb41e1e2cb2d1ab6dc2377e3c1fb2954105826d0
diff --git a/docker/swarm/stack/jenkins/master.yml b/docker/swarm/stack/jenkins/master.yml
index f6d12e5..bc01e92 100644
--- a/docker/swarm/stack/jenkins/master.yml
+++ b/docker/swarm/stack/jenkins/master.yml
@@ -1,6 +1,6 @@
 parameters:
   _param:
-    docker_image_jenkins: tcpcloud/jenkins:2.63
+    docker_image_jenkins: tcpcloud/jenkins:2.71
     jenkins_master_extra_opts: ""
     jenkins_master_executors_num: 4
   docker: