Ticket 48924 - Fixup tombstone task needs to set proper flag when updating tombstones
Bug Description: The fixup tombstone task is not updating tombstones due to
TOMBSTONE_INCLUDE not being set when looking up the entry to
modify.
Fix Description: If fixing up tombstones called find_entry2modify_only_ext with
the TOMBSTONE_INCLUDED flag.
https://fedorahosted.org/389/ticket/48924
Reviewed by: nhosoi(Thanks!)
(cherry picked from commit 8cfb650170bbb4f6ce328b827dc294437ee38c4b)