Use proper ant file glob for copying pip.log.

* modules/openstack_project/files/jenkins_job_builder/config/pbr.yaml:
Jenkins requires a proper ant file glob as the source for the scp
plugin. The originally provided fully rooted path does not meet this
criteria. Copy the pip log from Jenkins' homedir to the job workspace
and swap the SCP file path with an ant glob that is valid.

Change-Id: If9f00a9c699d62ba38f46b55b52ef86203631fae
Reviewed-on: https://review.openstack.org/36178
Reviewed-by: James E. Blair <corvus@inaugust.com>
Approved: Monty Taylor <mordred@inaugust.com>
Reviewed-by: Monty Taylor <mordred@inaugust.com>
Tested-by: Jenkins