Set nginx logging to level info again.

core/nginx/conf/nginx.conf

@@ -1,7 +1,7 @@
 #  Basic configuration
 user nginx;
 worker_processes auto;
-error_log /dev/stderr debug;
+error_log /dev/stderr info;
 pid /var/run/nginx.pid;
 load_module "modules/ngx_mail_module.so";