prservice.py: fix NameError: global name 'host' is not defined

* http://git.openembedded.org/openembedded-core/commit/?id=e00f49de8b1f79c3e07b887d257bd75a46052fa0
  removed host and port variables

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>