dbcheck: add support for restoring missing forward links
This recovers broken databases with duplicate and missing
forward links.
See commit
a25c99c9f1fd1814c56c21848c748cd0e038eed7 for
the fix that prevents to problem from happening.
BUG: https://bugzilla.samba.org/show_bug.cgi?id=13228
Pair-Programmed-With: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Ralph Boehme <slow@samba.org>
Signed-off-by: Stefan Metzmacher <metze@samba.org>
(cherry picked from commit
5bf823d68bd33ee3160175a18a3838eff4e3cbb2)