Merge pull request #9671 from ceph/hammer-rgw-copy-if-newer

hammer: rgw: backport rgwx-copy-if-newer for radosgw-agent

Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Nathan Cutler <ncutler@suse.com>

diff --cc src/rgw/rgw_op.cc
Simple merge

diff --cc src/rgw/rgw_rados.cc
Simple merge

diff --cc src/rgw/rgw_rados.h
Simple merge

diff --cc src/rgw/rgw_rest_s3.cc
Simple merge