SYSDB: Better debugging for email conflicts
Add DEBUG message when conflicts in FQ names or emails
are detected.
Also improve man page to hint on how to work around issue
with conflicting emails.
Note: We store emails in two different attributes in sysdb:
- SYSDB_USER_EMAIL
- SYSDB_NAME_ALIAS - this one is lowercased and used in getpwnam
searches.
Resolves:
https://fedorahosted.org/sssd/ticket/3293
Reviewed-by: Fabiano Fidêncio <fidencio@redhat.com>