(maint) Update server URI in tutorial request
(maint) Update server URI in tutorial request

Fix the server URI used as target endpoint for an inventory request by
the controller of tutorial step #9.

MikaelSmith/cpp-pcp-client,MikaelSmith/cpp-pcp-client,MikaelSmith/cpp-pcp-client,puppetlabs/cpp-pcp-client,puppetlabs/cpp-pcp-client,puppetlabs/cpp-pcp-client,MikaelSmith/cpp-pcp-client,puppetlabs/cpp-pcp-client,MikaelSmith/cpp-pcp-client