fix variable substitution when reporting NSX controller endpoint

- correctly substitute variable which contain NSX controller endpoint
  value
- report correct provider name in debug message of `rrpm' package
  provider, right now it misleads reader

Change-Id: I325ba8ef271cc54ed9a48d6fb0b3b1afcbd98c10
Closes-bug: #1380991
Merge "fix variable substitution when reporting NSX controller endpoint"