Added cache header for static and public files (refs #18984).

7.Nginx/vhost_skyreach.conf

@@ -15,9 +15,15 @@ server {
 
 	location /media {
 		alias /home/skyreach/htdocs/skyreach_site/media;
+		expires 30d;
+		add_header Pragma public;
+		add_header Cache-Control "public";
 	}
 	location /static {
 		alias /home/skyreach/htdocs/skyreach_site/static;
+		expires 30d;
+		add_header Pragma public;
+		add_header Cache-Control "public";
 	}
 
 	location /remote-event/ {