fixed typo

packages/app/src/server/crowi/index.js

@@ -18,7 +18,7 @@ import AclService from '../service/acl';
 import AttachmentService from '../service/attachment';
 import { SlackIntegrationService } from '../service/slack-integration';
 import { UserNotificationService } from '../service/user-notification';
-import Actiity from '../models/activity';
+import Activity from '../models/activity';
 
 const logger = loggerFactory('growi:crowi');
 const httpErrorHandler = require('../middlewares/http-error-handler');
@@ -307,7 +307,7 @@ Crowi.prototype.setupModels = async function() {
   allModels = models;
 
   // include models that independent from crowi
-  allModels.Activity = Actiity;
+  allModels.Activity = Activity;
 
   Object.keys(allModels).forEach((key) => {
     return this.model(key, models[key](this));