[6.17.z] Fix typo in capsule_setup helper

[Satellite-QE]

Cherrypick of PR: #17657

Problem Statement

Recent change in PR #17489 updated capsule_setup helper, which now fails with below error

failed on setup with "dynaconf.vendor.box.exceptions.BoxKeyError: "'DynaBox' object has no attribute 'rhelsource'". Did you mean: 'rhel_source'?"

Solution

Fix typo in capsule_setup helper

Related Issues

[Satellite-QE]

trigger: test-robottelo
pytest: tests/foreman/destructive/test_puppetplugin.py::test_positive_enable_disable_logic

[Satellite-QE]

PRT Result

Build Number: 10273
Build Status: UNSTABLE
PRT Comment: pytest tests/foreman/destructive/test_puppetplugin.py::test_positive_enable_disable_logic --external-logging
Test Result : ================= 1 failed, 17 warnings in 1966.96s (0:32:46) ==================

[Gauravtalreja1]

PRT failure look unrelated to the changes in PR, instead it looks like a bug in Puppet removal

[ogajduse]

This patch fixes what it is supposed to fix. As Gaurav pointed out, the PRT failure hints at some other issue.