fix: add default for unbound variable
fix: add default for unbound variable

[#167185664](https://www.pivotaltracker.com/story/show/167185664)

Co-authored-by: Clay Kauzlaric <b161dd152ba17987305414195d30c2af856d229f@pivotal.io>

cloudfoundry-incubator/cf-routing-release,cloudfoundry-incubator/cf-routing-release,cloudfoundry-incubator/cf-routing-release