Fix issue in paramiko test script
Fix issue in paramiko test script

Identified by manual pylint run (script not normally covered by pylint).

Code was moved from st2common/bin/paramiko_ssh_evenlets_tester.py
to st2common/st2common/ssh/parallel_ssh.py in
081d2efd82b630192456a86004e8178b901ca2fb (2015-07-31)

Then it moved to st2actions/st2actions/runners/ssh/parallel_ssh.py in
82c25088af3420cb94915e89ec35d77e9a260e55 (2015-08-06)
This change did not, however, update the imports in
st2common/bin/paramiko_ssh_evenlets_tester.py

Then it moved to contrib/runners/ssh/parallel_ssh.py in
40d927094c9d9f09deab848657ce71a84fd08d09 (2016-07-21)

Then it moved to st2common/st2common/runners/parallel_ssh.py in
718a0295c7e7c3566825ea975c54f12a4b855ac1 (2016-09-20)

So, this has been broken since 2015, and no one has complained.
But, maybe an eventlet tester will come in handy, so I'll just fix
the import and be on my way.

What a satisfying end to a twisty git spelunking session.

StackStorm/st2,nzlosh/st2,Plexxi/st2,StackStorm/st2,StackStorm/st2,nzlosh/st2,nzlosh/st2,Plexxi/st2,Plexxi/st2,Plexxi/st2,StackStorm/st2,nzlosh/st2