[6.15.z] Fix getting exit code on capsule tunnel error

[Satellite-QE]

Cherrypick of PR: #14821

Problem Statement

There is a problem with capsule tunnel error handling. It throws TypeError: 'int' object is not subscriptable. By checking ssh2.channel.Channel.get_exit_status documentation it is obvious that channel.get_exit_status()[1] could never work since it was added.

Solution

Replace channel.get_exit_status() by channel.get_exit_signal() which is way more verbose providing not only return code but also error message and exit signal.

Related Issues

[Satellite-QE]

trigger: test-robottelo
pytest: tests/foreman/api/test_capsule.py::test_positive_update_url

[Satellite-QE]

PRT Result

Build Number: 6584
Build Status: SUCCESS
PRT Comment: pytest tests/foreman/api/test_capsule.py::test_positive_update_url --external-logging
Test Result : ================== 1 passed, 9 warnings in 728.95s (0:12:08) ===================