fix puppet agent server setting.
Created by: rendhalver
As pointed out in #125 version 4.9.4 and 4.10.0 use a different server when run as the agent or as a manual run. https://tickets.puppetlabs.com/browse/PUP-7434
The current config sets server in the agent section. We may need to move that to the main section and ensure it is absent in agent.