move proxy intercept errors to error-pages.conf

nginx.conf

@@ -23,7 +23,5 @@ http {
 	gzip_http_version 1.1;
 	gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;
 
-	proxy_intercept_errors on;
-
 	include /etc/nginx/sites/*;
 }