Jenkins: add blueocean plugin

Change-Id: Ibe562a9bd8141f76eed46cc1ce134b3084e23439
diff --git a/jessie-amd64-jenkins-master/plugins.txt b/jessie-amd64-jenkins-master/plugins.txt
index 5eb287a..c473b38 100644
--- a/jessie-amd64-jenkins-master/plugins.txt
+++ b/jessie-amd64-jenkins-master/plugins.txt
@@ -1,6 +1,7 @@
 amazon-ecs:1.26
 build-name-setter:2.0.4
 build-timeout:1.19
+blueocean:1.23.2
 copyartifact:1.43
 docker-plugin:1.1.9
 docker-slaves:1.0.7