Don't report 504 as error to New Relic

504 is essentially ImgFlo's 404, so it shouldn't be sent to New Relic as an error in order to prevent false alarms.

Author: bergie

newrelic.js

@@ -21,4 +21,11 @@ exports.config = {
      */
     level : 'info'
   }
+  /**
+   * Don't report certain types of failures as errors
+   */
+  error_collector : {
+    enabled : true,
+    ignore_status_codes : [404,504]
+  }
 };