[SSSD] [sssd PR#947][comment] tests: fix race conditions in integration tests

[pbrezina]

URL: https://github.com/SSSD/sssd/pull/947
Title: #947: tests: fix race conditions in integration tests

pbrezina commented:
"""
This is exactly the reason why it has not been fixed for two+ years. @sumit-bose @thalman @mzidek-rh can any of you chime in?
"""

See the full comment at https://github.com/SSSD/sssd/pull/947#issuecomment-561264554