XenAPI: Fix deprecated config options

I346ee0248c03e60716bd7dc4a5ee4493610867cb broke the XenServer CI as
devstack was still setting the deprecated config options.

Change-Id: Icd84212e97a9d5e007745be8096fa552bc23cb6f
diff --git a/lib/nova_plugins/hypervisor-xenserver b/lib/nova_plugins/hypervisor-xenserver
index c37969b..0dba471 100644
--- a/lib/nova_plugins/hypervisor-xenserver
+++ b/lib/nova_plugins/hypervisor-xenserver
@@ -49,9 +49,9 @@
     fi
     read_password XENAPI_PASSWORD "ENTER A PASSWORD TO USE FOR XEN."
     iniset $NOVA_CONF DEFAULT compute_driver "xenapi.XenAPIDriver"
-    iniset $NOVA_CONF DEFAULT xenapi_connection_url "$XENAPI_CONNECTION_URL"
-    iniset $NOVA_CONF DEFAULT xenapi_connection_username "$XENAPI_USER"
-    iniset $NOVA_CONF DEFAULT xenapi_connection_password "$XENAPI_PASSWORD"
+    iniset $NOVA_CONF xenserver connection_url "$XENAPI_CONNECTION_URL"
+    iniset $NOVA_CONF xenserver connection_username "$XENAPI_USER"
+    iniset $NOVA_CONF xenserver connection_password "$XENAPI_PASSWORD"
     iniset $NOVA_CONF DEFAULT flat_injected "False"
     # Need to avoid crash due to new firewall support
     XEN_FIREWALL_DRIVER=${XEN_FIREWALL_DRIVER:-"nova.virt.firewall.IptablesFirewallDriver"}