Remove nginx default conf

This patch make sure Default.conf from nginx
is remove as it causes socket conflict when
we deploy it on metal. Also, we remove the
task created by kevin for Q -> S deployments
as it is not required to S -> T upgrades.

Change-Id: Ic2e3bc66161217b2884001018a706dbe2187c498

tasks/keystone_nginx.yml

@@ -27,11 +27,9 @@
     - Manage LB
     - Restart web server
 
-# TODO(cloudnull):
-# This is to cater for Q-R, R-S upgrades and can be removed in T
-- name: Remove legacy nginx config
+- name: Remove default nginx config
   file:
-    path: /etc/nginx/sites-enabled/keystone-wsgi-admin.conf
+    path: /etc/nginx/conf.d/default.conf
     state: absent
   notify:
     - Manage LB