jjb: xci: Fix trigger for cleanup jobs

jjb: xci: Fix trigger for cleanup jobs

Trigger should only run on change-merged and change-abandonded
The documentation could be imporved more explicitly here:
https://docs.openstack.org/infra/jenkins-job-builder/triggers.html#trigger-on
but the modified lines do not take true or false they stand alone

Fixes: ea33eda6954a ("jjb: infra: bifrost-cleanup-job: Do not trigger on new patchsets")
Fixes: f6bba721fd13 ("jjb: infra: bifrost-cleanup-job: Do not trigger on patchset creation")
Change-Id: Ibc574220ea86c5a039855d6f4fe35eef0aac7e0e
Signed-off-by: Aric Gardner <agardner@linuxfoundation.org>
Signed-off-by: Markos Chandras <mchandras@suse.de>