Update the vnc config options group 'DEFAULT' to 'vnc'

n-api log output WARNINGs that vnc config options group 'DEFAULT'
is deprecated. New vnc config options group is 'vnc'.
This is change of Nova.[1]
This patch changes the vnc config options group 'DEFAULT' to 'vnc'.

[1] https://bugs.launchpad.net/nova/+bug/1447528

Change-Id: If54f750bac83298e90bdca27b5992fe2e5fbb712
Closes-Bug: 1483583
diff --git a/lib/nova_plugins/hypervisor-libvirt b/lib/nova_plugins/hypervisor-libvirt
index 8bbaa21..1b4f7ae 100644
--- a/lib/nova_plugins/hypervisor-libvirt
+++ b/lib/nova_plugins/hypervisor-libvirt
@@ -48,13 +48,13 @@
     iniset $NOVA_CONF DEFAULT firewall_driver "$LIBVIRT_FIREWALL_DRIVER"
     # Power architecture currently does not support graphical consoles.
     if is_arch "ppc64"; then
-        iniset $NOVA_CONF DEFAULT vnc_enabled "false"
+        iniset $NOVA_CONF vnc enabled "false"
     fi
 
     # arm64-specific configuration
     if is_arch "aarch64"; then
         # arm64 architecture currently does not support graphical consoles.
-        iniset $NOVA_CONF DEFAULT vnc_enabled "false"
+        iniset $NOVA_CONF vnc enabled "false"
     fi
 
     # File injection is being disabled by default in the near future -
@@ -65,9 +65,9 @@
         iniset $NOVA_CONF libvirt connection_uri "parallels+unix:///system"
         iniset $NOVA_CONF libvirt images_type "ploop"
         iniset $NOVA_CONF DEFAULT force_raw_images  "False"
-        iniset $NOVA_CONF DEFAULT vncserver_proxyclient_address  $HOST_IP
-        iniset $NOVA_CONF DEFAULT vncserver_listen $HOST_IP
-        iniset $NOVA_CONF DEFAULT vnc_keymap
+        iniset $NOVA_CONF vnc vncserver_proxyclient_address  $HOST_IP
+        iniset $NOVA_CONF vnc vncserver_listen $HOST_IP
+        iniset $NOVA_CONF vnc keymap
     fi
 }