Adds backwards compatibility for node parameter used by strategies. If the node value is set by the user configuration it will override the value for compute_node which is the value used by the strategies now. This change was introduced in: https://review.opendev.org/#/c/656622/ Resolution discussed in the meeting on the 5th of June 2019 https://eavesdrop.openstack.org/meetings/watcher/2019/watcher.2019-06-05-08.00.log.html Change-Id: Idaea062789a6b169e64f556fecc34cfbaaee5076