upgrade-parallel/rgw: use different client for final run

rgw task doesn't like to be stopped, then started as the same client.
That is probably fixable (it's just the archive/apache.$client dir) but
I didn't look closely.  Avoid the issue by using different client ids
here.

Signed-off-by: Sage Weil <sage@inktank.com>
upgrade: do not wait for full quorum on mixed-version mon cluster

It won't happen