Added empty parameter check
Added empty parameter check

Added a check for null parameter as this is what VSTS passes
rfennell/vNextBuild,ChrisLGardner/vNextBuild,ChrisLGardner/vNextBuild,rfennell/vNextBuild,ChrisLGardner/vNextBuild,rfennell/vNextBuild,ChrisLGardner/vNextBuild,rfennell/vNextBuild