call .lines.to_a instead of .to_a on gwcostmetric for ruby 1.9 compatibi...

The `setgateways` method in the `winnetwork` provider calls `.to_a on` a string.

     oInParam.GatewayCostMetric = gateways_hash[:gwcostmetric].to_a

For ruby 1.9 and newer versions of puppet enterprise this should be changed to `.lines.to_a`.

     oInParam.GatewayCostMetric = gateways_hash[:gwcostmetric].lines.to_a