[8.0][Swarm] Env with Ceph and Network template fails during deploy

[Dmitry]

Run
https://github.com/openstack/fuel-qa/blob/stable/8.0/fuelweb_test/tests/test_net_templates.py#L119

deploy_ceph_net_tmpl test that consists of the next steps:

1. Revert snapshot with 5 slaves
2. Create cluster (HA) with Neutron VLAN/VXLAN/GRE
3. Add 3 controller + ceph nodes
4. Add 2 compute + ceph nodes
5. Upload 'ceph' network template
6. Create custom network groups basing
               on template endpoints assignments
7. Run network verification
8. Deploy cluster
9. Run network verification
10. Run health checks (OSTF)
11. Check L3 network configuration on slaves
12. Check that services are listening on their networks only

Actual Result:
On the 8th step we have rare problem in deploy:
AssertionError: Task 'deploy' has incorrect status. error != ready, 'Deployment has failed.

https://github.com/openstack/fuel-qa/blob/stable/8.0/fuelweb_test/models/fuel_web_client.py#L732