hack/multi-node: remove ref to non-existent config file
hack/multi-node: remove ref to non-existent config file

ericchiang/bootkube,diegs/bootkube,dghubble/bootkube,hongchaodeng/bootkube,diegs/bootkube,hongchaodeng/bootkube,dghubble/bootkube,hongchaodeng/bootkube,kubernetes-incubator/bootkube,ericchiang/bootkube,dghubble/bootkube,ericchiang/bootkube,kubernetes-incubator/bootkube,diegs/bootkube,kubernetes-incubator/bootkube