(QENG-1225) Bug fix in `Pkg::Util::Jenkins.poll_jenkins_job`

Apparently sometimes the `pl:jenkins:uber_build` dynamic job trigger hasn't
quite propagated through the Jenkins build system before we reach
`pl:jenkins:uber_build_with_polling` which can lead to nil result when using
the `job_json['lastBuild']` so here's a workaround.

Signed-off-by: Wayne Warren <waynr@sdf.org>
(QENG-1225) Add support for msi job.

Signed-off-by: Wayne Warren <waynr@sdf.org>