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

[pbrezina]

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

pbrezina commented:
"""
Ok, I switched order of patches and added two more:
* ci: do not build secrets on rhel6 -- this should suppress building secrets on rhel6
* sss_iobuf: fix 'read' shadows a global declaration -- one more shadowed name
"""

See the full comment at https://github.com/SSSD/sssd/pull/198#issuecomment-289771297