Fix and update capsule certificate validation

[Griffin-Sullivan]

Problem Statement

The original qpid RPM being used to validate the capsule certs in test_positive_validate_capsule_certificate was removed recently.

Solution

Remove the rpm2cpio line and use the apache cert that was generated. Also clean up old code that relied on the BZ.

Related Issues

PRT test Cases example

trigger: test-robottelo pytest: tests/foreman/destructive/test_katello_certs_check.py::test_positive_validate_capsule_certificate

[Griffin-Sullivan]

trigger: test-robottelo pytest: tests/foreman/destructive/test_katello_certs_check.py::test_positive_validate_capsule_certificate

[Satellite-QE]

PRT Result

Build Number: 6463
Build Status: SUCCESS
PRT Comment: pytest tests/foreman/destructive/test_katello_certs_check.py::test_positive_validate_capsule_certificate --external-logging
Test Result : ================= 1 passed, 13 warnings in 1313.32s (0:21:53) ==================