Do not require compute.vnc params

This patch update nova-compute jinja template for Newton to
do not require vnc params as they are not mandatory.

Change-Id: Ia7c9c879f47664ed48f67e19e1c5e57a729b5f0c
diff --git a/nova/files/newton/nova-compute.conf.Debian b/nova/files/newton/nova-compute.conf.Debian
index 30667de..cad6f4f 100644
--- a/nova/files/newton/nova-compute.conf.Debian
+++ b/nova/files/newton/nova-compute.conf.Debian
@@ -107,15 +107,23 @@
 
 [vnc]
 enabled = true
+{%- if compute.vncproxy_url is defined %}
 novncproxy_base_url={{ compute.vncproxy_url }}/vnc_auto.html
+{%- endif %}
+{%- if compute.get('bind', {}).get('vnc_port') %}
 novncproxy_port={{ compute.bind.vnc_port }}
+{%- endif %}
 vncserver_listen=0.0.0.0
+{%- if compute.get('bind', {}).get('vnc_address') %}
 vncserver_proxyclient_address={{ compute.bind.vnc_address }}
+{%- endif %}
 keymap = {{ compute.get('vnc_keymap', 'en-us') }}
 
 [spice]
 enabled = false
+{%- if compute.vncproxy_url is defined %}
 html5proxy_base_url = {{ compute.vncproxy_url }}/spice_auto.html
+{%- endif %}
 
 [cache]
 {%- if compute.cache is defined %}