fix tests

src/reverseproxy.js

@@ -185,12 +185,12 @@ function validateCertificate(location, domainObject, certificate) {
 }
 
 function reload(callback) {
-    if (constants.TEST) return callback();
+    if (constants.TEST) return callback(null);
 
     shell.sudo('reload', [ RESTART_SERVICE_CMD, 'nginx' ], {}, function (error) {
         if (error) return callback(new BoxError(BoxError.NGINX_ERROR, `Error reloading nginx: ${error.message}`));
 
-        callback();
+        callback(null);
     });
 }