[8.0] Deployment of changes can fail during testing HA mode on scalability

[Alexander Gromov]

Reproduced on CI:
https://patching-ci.infra.mirantis.net/job/8.0.system_test.ubuntu.ha_neutron_tun_scale/11/testReport/%28root%29/neutron_tun_scalability/neutron_tun_scalability/
https://patching-ci.infra.mirantis.net/job/8.0.system_test.ubuntu.ha_neutron_tun_scale/17/testReport/%28root%29/neutron_tun_scalability/neutron_tun_scalability/

Steps to reproduce:
1. Create cluster
2. Add 1 controller node
3. Deploy the cluster
4. Add 2 controller nodes
5. Deploy changes
6. Run network verification
7. Add 2 controller 1 compute nodes
8. Deploy changes

or use neutron_tun_scalability test from fuel-qa

Expected results:
Deployment is successful

Actual result:
Sometimes deployment can fail with the following error:
http://paste.openstack.org/show/498742/

The following errors were found in syslog of node-2:
http://paste.openstack.org/show/498743/

Diagnostic snapshot link: https://patching-ci.infra.mirantis.net/job/8.0.system_test.ubuntu.ha_neutron_tun_scale/17/artifact/logs/fail_error_neutron_tun_scalability-fuel-snapshot-2016-05-21_22-42-37.tar.xz

[Alexey Stupnikov (astupnikov)]

We no longer support MOS5.1, MOS6.0, MOS6.1
We deliver only Critical/Security fixes to MOS7.0, MOS8.0.
We deliver only High/Critical/Security fixes to MOS9.2.