Add default jenkins version to Makefile of master image

When building the jenkins-docker/master image manually using the
provided Makefile the build failed, because the JENKINS_WAR_VER
and JENKINS_WAR_SHA were not set.

To allow an easier manual build this change sets a default Jenkins
version (2.25).

Change-Id: Ieeee8ffbbc722be508c5caa6ac47943b6dc9249f
1 file changed
tree: 41614115287427061fbb8cc2bc9923fbb3957fab
  1. jenkins/
  2. jenkins-docker/
  3. worker/
  4. .gitignore