Jenkinsfile: abort previous build for the same job
Jenkinsfile: abort previous build for the same job

Script will abort previous running build if a new build is in progress.
It checks running builds of current job and abort if there are some
ecxept the current one.
It will be helpful especially for Pull Requests builds to abort build
if PR was updated.

Signed-off-by: Dmytro Iurchuk <16ba42971a6f2e7a0d103a9f9b92eff4116e1776@luxoft.com>

Pelagicore/pelux-manifests,sashko/pelux-manifests