When specifying a SSH bastion host st2actionrunner leaks sockets and throws exceptions

[nmaludy]

SUMMARY

When specifying a bastion host for the SSH runners, st2actionrunner leaks sockets and throws exceptions when trying to close those sockets.

st2actionrunner-59c47ddcc8-9jjbl r1 2020-06-25 15:30:17,009 ERROR [-] Failed shutting down SSH connection to host: rndcas402
st2actionrunner-59c47ddcc8-9jjbl r1 Traceback (most recent call last):
st2actionrunner-59c47ddcc8-9jjbl r1   File "/opt/stackstorm/st2/local/lib/python2.7/site-packages/st2common/runners/parallel_ssh.py", line 218, in close
st2actionrunner-59c47ddcc8-9jjbl r1     self._hosts_client[host].close()
st2actionrunner-59c47ddcc8-9jjbl r1   File "/opt/stackstorm/st2/local/lib/python2.7/site-packages/st2common/runners/paramiko_ssh.py", line 462, in close
st2actionrunner-59c47ddcc8-9jjbl r1     self.socket.process.kill()
st2actionrunner-59c47ddcc8-9jjbl r1 AttributeError: 'Channel' object has no attribute 'process'

STACKSTORM VERSION

3.2.0

Additional Info

Looks to have been introduced here: #4881