Setting Up NServiceBus Registry Entries

This fixes an issue setting up NServiceBus Registry entries when running them for the first time. 
This never happened and users see the "Setup Screen" every time because the MachinePreparedKey was never created due to wrong concatenation (powershell was throwing an exception that was swallowed: cannot concat int32.)
Merge pull request #1807 from bholdt/patch-1

Setting Up NServiceBus Registry Entries