[SSSD] [sssd PR#198][comment] secrets: support https in proxy provider

[lslebodn]

URL: https://github.com/SSSD/sssd/pull/198
Title: #198: secrets: support https in proxy provider

lslebodn commented:
"""
rhel7 error
```
test_secrets.py::test_crd_ops PASSED
test_secrets.py::test_curlwrap_crd_ops FAILED
test_secrets.py::test_curlwrap_parallel PASSED
test_secrets.py::test_containers PASSED

======================= FAILURES==================================
_____________ test_curlwrap_crd_ops __________________________________
Traceback (most recent call last):
  File "/home/build/sssd/src/tests/intg/test_secrets.py", line 278, in test_curlwrap_crd_ops
    200)
  File "/home/build/sssd/src/tests/intg/test_secrets.py", line 207, in run_curlwrap_tool
    assert exp_http_code_str in out
AssertionError: assert 'Request HTTP code: 200' in ''
```

+ test_kcm_sec_* are failing as well on rhel7
``
"""

See the full comment at https://github.com/SSSD/sssd/pull/198#issuecomment-290052915