[tool] allow customizing parallelism for local_replica copy_from_remote

Allow passiing --tablet_copy_download_threads_nums_per_session to
specify the parallelism of local_replica copy_from_remote tool.

Change-Id: I17a5937b259ed22c987f6560ca5008afcb161f20
Reviewed-on: http://gerrit.cloudera.org:8080/16738
Tested-by: Kudu Jenkins
Reviewed-by: Alexey Serbin <aserbin@cloudera.com>
1 file changed