When printing AbstractBuild.BuildingRemotely message to log, also indicate any...

When printing AbstractBuild.BuildingRemotely message to log, also indicate any (non-self) labels of the node.
This is invaluable when diagnosing problems with a build on a cloud slave after the slave has been deprovisioned.
If the node name by itself does not indicate what type of machine it was, you would have a hard time guessing.