nginx: remove a few fields from json_reduced

This brings it in line with the non-JSON "reduced" log format.

roles/nginx/templates/nginx.conf.j2

@@ -50,9 +50,7 @@ http {
 
     log_format json_reduced escape=json
         '{'
-        '"remote_addr":"$remote_addr",'
         '"host":"$host",'
-        '"remote_user":"$remote_user",'
         '"time_local":"$time_local",'
         '"request_method":"$request_method",'
         '"request_uri":"$request_uri",'
@@ -60,8 +58,6 @@ http {
         '"body_bytes_sent":"$body_bytes_sent",'
         '"http_referrer":"$http_referer",'
         '"http_user_agent":"$http_user_agent",'
-        '"http_x_forwarded_for":"$http_x_forwarded_for",'
-        '"request_time":"$request_time",'
         # This was added to keep every log line unique as Loki drops
         # log line with the same timestamp and log text:
         # https://grafana.com/docs/loki/latest/overview/#timestamp-ordering