Strange env setup for test-softlayer-ubuntu1604-x64-1 (for the record)

[rvagg]

The "Environment variables", "Prepare jobs environment", and "Unset System Environment Variables" options below here are all odd here, the config change history records these changes are by @refack in September last year and I can't work out why. This machine shares jenkins-workspace role with test-packetnet-ubuntu1604-x64-1 and test-packetnet-ubuntu1604-x64-2 and neither of those have this special case. It's causing problems with the migration of linters from FreeBSD 10 to to these jenkins-workspace machines, mainly the "Unset System Environment Variables". Grepping for \WTe\W I can't find anything in the job configs so I'm going to guess that this was either a mistake or for some purpose that is no longer valid.

I'm unsetting these but recording here that they were set in case someone can identify the reason and thinks it needs to go back.