Test jobs failed with many threads errors on ubuntu

[Sergey Kraynev]

6.1.staging.ubuntu.bvt_2 job fails with several exceptions in threads:

Exception in thread Thread-174 (most likely raised during interpreter shutdown):Exception in thread Thread-40 (most likely raised during interpreter shutdown):
 Exception in thread Thread-24 (most likely raised during interpreter shutdown):Exception in thread Thread-34 (most likely raised during interpreter shutdown):
Traceback (most recent call last):Exception in thread Thread-92 (most likely raised during interpreter shutdown):Exception in thread Thread-180 (most likely raised during interpreter shutdown):
Traceback (most recent call last):
 Exception in thread Thread-18 (most likely raised during interpreter shutdown):Exception in thread Thread-110 (most likely raised during interpreter shutdown):Exception in thread Thread-82 (most likely raised during interpreter shutdown):
Traceback (most recent call last):
  File "/usr/lib/python2.7/threading.py", line 810, in __bootstrap_inner
  File "/home/jenkins/venv-nailgun-tests-2.9/local/lib/python2.7/site-packages/paramiko/transport.py", line 1642, in run
<type 'exceptions.AttributeError'>: 'NoneType' object has no attribute 'error'
Exception in thread Thread-142 (most likely raised during interpreter shutdown):
Traceback (most recent call last):
  File "/usr/lib/python2.7/threading.py", line 810, in __bootstrap_inner
  File "/home/jenkins/venv-nailgun-tests-2.9/local/lib/python2.7/site-packages/paramiko/transport.py", line 1642, in run
<type 'exceptions.AttributeError'>: 'NoneType' object has no attribute 'error'
 Exception in thread Thread-36 (most likely raised during interpreter shutdown):Exception in thread Thread-146 (most likely raised during interpreter shutdown):
 Exception in thread Thread-54 (most likely raised during interpreter shutdown):Exception in thread Thread-10 (most likely raised during interpreter shutdown):
Traceback (most recent call last):
  File "/usr/lib/python2.7/threading.py", line 810, in __bootstrap_inner
  File "/home/jenkins/venv-nailgun-tests-2.9/local/lib/python2.7/site-packages/paramiko/transport.py", line 1642, in run
<type 'exceptions.AttributeError'>: 'NoneType' object has no attribute 'error'
Exception in thread Thread-52 (most likely raised during interpreter shutdown):Exception in thread Thread-150 (most likely raised during interpreter shutdown):Exception in thread Thread-154 (most likely raised during interpreter shutdown):Exception in thread Thread-112 (most likely raised during interpreter shutdown):
 Exception in thread Thread-184 (most likely raised during interpreter shutdown):
 Exception in thread Thread-66 (most likely raised during interpreter shutdown):
Traceback (most recent call last):
 Exception in thread Thread-6 (most likely raised during interpreter shutdown):
Traceback (most recent call last):Exception in thread Thread-134 (most likely raised during interpreter shutdown):Exception in thread Thread-2 (most likely raised during interpreter shutdown):Exception in thread Thread-176 (most likely raised during interpreter shutdown):Exception in thread Thread-182 (most likely raised during interpreter shutdown):Segmentation fault

http://jenkins-product.srt.mirantis.net:8080/job/6.1.staging.ubuntu.bvt_2/118/console

I found similar bug https://bugs.launchpad.net/fuel/+bug/1416365, but it's fixed, so maybe some missed changes on lab need.

[Dennis Dmitriev (ddmitriev)]

Work on the issue is going in the https://bugs.launchpad.net/bugs/1455357 , so mark this one as a duplicate