Rename user limits api by user limits backend

lib/cartodb/api/map/preview-template-controller.js

@@ -30,7 +30,7 @@ function PreviewTemplateController (
     metadataBackend,
     pgConnection,
     authBackend,
-    userLimitsApi
+    userLimitsBackend
 ) {
     this.namedMapProviderCache = namedMapProviderCache;
     this.previewBackend = previewBackend;
@@ -39,7 +39,7 @@ function PreviewTemplateController (
     this.metadataBackend = metadataBackend;
     this.pgConnection = pgConnection;
     this.authBackend = authBackend;
-    this.userLimitsApi = userLimitsApi;
+    this.userLimitsBackend = userLimitsBackend;
 }
 
 module.exports = PreviewTemplateController;
@@ -50,7 +50,7 @@ PreviewTemplateController.prototype.register = function (mapRouter) {
         credentials(),
         authorize(this.authBackend),
         dbConnSetup(this.pgConnection),
-        rateLimit(this.userLimitsApi, RATE_LIMIT_ENDPOINTS_GROUPS.STATIC_NAMED),
+        rateLimit(this.userLimitsBackend, RATE_LIMIT_ENDPOINTS_GROUPS.STATIC_NAMED),
         cleanUpQueryParams(['layer', 'zoom', 'lon', 'lat', 'bbox']),
         namedMapProvider({
             namedMapProviderCache: this.namedMapProviderCache,