Org tables already have created and modified fields, so they

[are not needed](https://github.com/wekan/wekan/commit/2cedbcb9b334cd497874736bbb740a1d5c5acb6c#r34310611)
for add-missing-created-and-modified migration, so removing not needed migration.

Thanks to justinr1234 and xet7 !

Related #802

server/migrations.js

@@ -17,8 +17,6 @@ import Swimlanes from '../models/swimlanes';
 import Triggers from '../models/triggers';
 import UnsavedEdits from '../models/unsavedEdits';
 import Users from '../models/users';
-import Org from '../models/org';
-import OrgUser from '../models/orgUser';
 
 // Anytime you change the schema of one of the collection in a non-backward
 // compatible way you have to write a migration in this file using the following
@@ -705,8 +703,6 @@ const firstBatchOfDbsToAddCreatedAndUpdated = [
   Swimlanes,
   Triggers,
   UnsavedEdits,
-  Org,
-  OrgUser,
 ];
 
 firstBatchOfDbsToAddCreatedAndUpdated.forEach(db => {
@@ -741,8 +737,6 @@ const modifiedAtTables = [
   Triggers,
   UnsavedEdits,
   Users,
-  Org,
-  OrgUser,
 ];
 
 Migrations.add('add-missing-created-and-modified', () => {