In previous 'rsync_then_merge' remote objects are merged with
rsync'ed local objects, but remote metadata is not merged with local
one. Account/Container replicator sometimes uses rsync for db sync if
there is a big difference of record history in db files between 'local'
and 'remote' servers. If replicator needs to rsync local db to remote
but metadata in local db is older, older info of metadata can be
distributed then some metadata values can be missing or go back to older.
This patch fixes this problem by merging 'remote' metadata with
rsync'ed local db file.
Closes-Bug: #1570118
Change-Id: Icdf0a936fc456c5462471938cbc365bd012b05d4
843184f3fe