ldb: version 1.3.1

ldb: version 1.3.1

* Intersect the index from SCOPE_ONELEVEL with the index for the search expression
  (bug #13191)
* smaller/greater comparison tests
* Show the last successful DN when failing to parse LDIF
* ldb_index: Add an attriubute flag to require a unique value.
* silence some clang warnings in picky developer mode

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>