Changes

ansible/setup-jenkins: install rsync

After recent refactoring of the gerrit-binpkgs job, rsync is now
requried on the jenkins nodes. It was installed on the ones where I
tested, but not on all of them.

Fixes: b2e12851 ("OBS: move gerrit-binpkgs logic to separate script")
Change-Id: Ic8ffd61fc2c89574085e9c3abbceb554f3c5da6a