[SSSD] [sssd PR#1010][comment] man: in sssd-ipa clarified trusted domains section

[pbrezina]

URL: https://github.com/SSSD/sssd/pull/1010
Title: #1010: man: in sssd-ipa clarified trusted domains section

pbrezina commented:
"""
I believe there should be "A trusted domain configuration can be set either *by* using". @justin-stephenson can you please check this commit for grammar? Thank you.
"""

See the full comment at https://github.com/SSSD/sssd/pull/1010#issuecomment-607143617