[LAE] Block Dubbot (#4653)

I hate to do it, but it's bringing things down and it's the end of the
day.

roles/nginxplus/files/conf/http/lae-prod.conf

@@ -45,6 +45,9 @@ server {
         proxy_set_header X-Forwarded-Host $host;
         proxy_cache laeprodcache;
         health_check interval=10 fails=3 passes=2;
+        if ($http_user_agent ~ (Dubbotbot) ) {
+          return 403;
+        }
         proxy_intercept_errors on;
         limit_req zone=lae-prod-ratelimit burst=80 nodelay;
     }