Certificates permission fixed for libvirt vnc+tls

  * Nova and libvirt-qemu users must have read acces to cert files.
    User libvirt-qemu added to Nova group in compute state.

Change-Id: Ief10055b96c61865660b969531f63b89bfb16376
diff --git a/salt/minion/cert/libvirtd/vnc_server.yml b/salt/minion/cert/libvirtd/vnc_server.yml
index c49852e..cf60c12 100644
--- a/salt/minion/cert/libvirtd/vnc_server.yml
+++ b/salt/minion/cert/libvirtd/vnc_server.yml
@@ -22,6 +22,6 @@
           key_file: ${_param:qemu_vnc_server_ssl_key_file}
           cert_file: ${_param:qemu_vnc_server_ssl_cert_file}
           ca_file: ${_param:qemu_vnc_ssl_ca_file}
-          user: libvirt-qemu
-          group: libvirt-qemu
+          user: root
+          group: nova
           mode: 640