[SSSD] [sssd PR#978][comment] Fix another build failure with python 3.8

[pbrezina]

URL: https://github.com/SSSD/sssd/pull/978
Title: #978: Fix another build failure with python 3.8

pbrezina commented:
"""
Thank you. Ack.
"""

See the full comment at https://github.com/SSSD/sssd/pull/978#issuecomment-581873555