Maintenance: Drop elasticsearch.conf for nginx (contrib)

Elasticsearch does support various authentication methods (not just for paying customers). 

The configuration file causes overhead and actually is invalid. Port 9200 is being used already which causes either nginx or elasticsearch to fail.

contrib/nginx/elasticsearch.conf

@@ -1,20 +0,0 @@
-#
-# this is the nginx config for elasticsearch with authentication for remote login
-# you need to create the auth file /etc/nginx/.htpasswd-elasticsearch with you username and password
-# this can be done on the shell via: 'htpasswd -b -c /etc/nginx/.htpasswd-elasticsearch USERNAME PASSWORD'
-#
-
-upstream elasticsearch {
-    server 127.0.0.1:9200;
-}
-
-server {
-    listen 9200;
-
-    auth_basic "Elasticsearch";
-    auth_basic_user_file /etc/nginx/.htpasswd-elasticsearch;
-
-    location / {
-        proxy_pass http://elasticsearch;
-    }
-}