Make reporturl configurable

[promasu]

With Foreman migrating their reports format and the need to use a dedicated plugin to process them there is the need to make the reporturl parameter in puppet.conf configurable to ensure Puppet with foreman reporting works with Foreman > 3.3

see https://community.theforeman.org/t/migrating-reports-to-the-new-format-in-foreman-3-2/
ref #221