Update krew plugin configuration

cmd/plugin/ingress-nginx.yaml.tmpl

@@ -6,7 +6,7 @@ spec:
   shortDescription: Interact with ingress-nginx
   description: |
     The official kubectl plugin for ingress-nginx.
-  version: %%%tag%%%
+  version: v%%%tag%%%
   homepage: https://kubernetes.github.io/ingress-nginx/kubectl-plugin/
   platforms:
   - uri: https://github.com/kubernetes/ingress-nginx/releases/download/nginx-%%%tag%%%/kubectl-ingress_nginx-darwin-amd64.tar.gz