Ironic baremetal node won't reassigned to another ironic-conductor node after stopping conductor service

[Georgy Dyuldin]

Steps to reproduce:
* Deploy OpenStack with Fuel 8.0 (release)
  1 controller node
  1 compute node
  3 ironic-conductor nodes
  1 ironic-compute node
* Launch 1 ironic instance
* Search ironic-conductor node assigned to ironic-compute node (it contains folder /var/lib/remote/ironic/<ironic_node_uuid>/)
* Stop ironic-conductor service (with `service ironic-conductor stop`)
* Wait 10 minutes
* Search ironic-conductor node assigned to ironic-compute node again

Expected result:
Ironic-conductor node assigned to ironic-compute is changed.

Actual result:
Ironic-conductor node assigned to ironic-compute is not changed.

Environment:
Version - {"release": "8.0", "auth_required": true, "api": "1", "openstack_version": "liberty-8.0", "feature_groups": ["mirantis"]}

[Bug Checker Bot (bug-checker)]

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version

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[Andrey Shestakov (ashestakov)]

/var/lib/remote/ironic/<ironic_node_uuid> - this folder contains config and images required only for provision node.
after instance deployed successfully, folder is not required and node should not be assigned to any conductor service.
also we using same hostname "ironic-compute" for all ironic compute services.