SYSDB: Augment sysdb_try_to_find_expected_dn to match search base as well

In cases where the domain name in sssd.conf does not match the AD
domain, our previous matching process wouldn't match. This patch
augments the matching as follows:
    - the search base is known to sysdb_try_to_find_expected_dn and is
      expected to be non-NULL
    - the existing matching is ran first
    - during the search base, matching, all the non-DC components are
      stripped from the search base to 'canonicalize' the search base
    - if only a single entry that matches with a non-DC DN component
      (matching with a DC component would mean the DN comes from a
      different domain) then this entry is a match and is returned

Resolves:
https://fedorahosted.org/sssd/ticket/3199

Reviewed-by: Sumit Bose <sbose@redhat.com>

0 files changed, 0 insertions, 0 deletions