Fix ReallyCrash error from gometalinter
Fix ReallyCrash error from gometalinter

denen99/mesos-dns,mesosphere/mesos-dns,denen99/mesos-dns,vivint-smarthome/mesos-dns,alberts/mesos-dns,saagie/mesos-dns,mesosphere/mesos-dns,alberts/mesos-dns,vivint-smarthome/mesos-dns