Set libvirt exporter image in default role

drive-by: fix vencrypt issuer config
diff --git a/roles/defaults/vars/main.yml b/roles/defaults/vars/main.yml
index e3e3795..fb12b84 100644
--- a/roles/defaults/vars/main.yml
+++ b/roles/defaults/vars/main.yml
@@ -94,6 +94,7 @@
   kube_state_metrics: registry.k8s.io/kube-state-metrics/kube-state-metrics:v2.9.2
   kubectl: docker.io/bitnami/kubectl:1.27.3
   libvirt: quay.io/vexxhost/libvirtd@sha256:480d8736954cdc01c1d6f0c625ba147935ce4e5af25828f6d3fbcd18e6dc283a # image-source: quay.io/vexxhost/libvirtd:zed
+  libvirt_exporter: docker.io/vexxhost/libvirtd-exporter:latest
   local_path_provisioner_helper: docker.io/library/busybox:1.36.0
   local_path_provisioner: docker.io/rancher/local-path-provisioner:v0.0.24
   loki_gateway: docker.io/nginxinc/nginx-unprivileged:1.19-alpine
diff --git a/roles/libvirt/vars/main.yml b/roles/libvirt/vars/main.yml
index 37e2ce8..ed0d29f 100644
--- a/roles/libvirt/vars/main.yml
+++ b/roles/libvirt/vars/main.yml
@@ -31,5 +31,6 @@
       default_tls_x509_verify: "1"
       vnc_tls: "1"
     vencrypt:
-      issuer: Issuer
-      name: libvirt-vnc-ca
+      issuer:
+        kind: Issuer
+        name: libvirt-vnc-ca