_ensureIndex has been deprecated

[polygonwood]

I'm having an issue:

• Give an expressive description of what is went wrong
  startup of application shows these messages :
  ...
  [FilesCollection.storagePath] Set to: assets/app/uploads/uploadedFiles
  D20220124-20:50:03.195(1) (collection.js:743) _ensureIndex has been deprecated, please use the new 'createIndex' instead, index: {"createdAt":1}
  ...

• Version of Meteor-Files you're experiencing this issue ostrio:files 2.0.1

• Version of Meteor you're experiencing this issue 2.6-beta.4

• Where this issue appears? OS (Mac/Win/Linux)? Browser name and its version? Linux

• Is it Client or Server issue? - Server

• Post Client and/or Server logs with enabled debug option, you can enable "debug" mode in Constructor

I had an issue and I've solved it on my own:

• Provide a description of steps that you've followed to solve the problem
• Provide links to websites and/or pages with the information that helped you (if there are any)

I have a suggestion:

• Describe your feature / request : adapt mongo 5 createIndex as suggested
• How you going to use it? Give a usage example(s)

Documentation is missing something or incorrect (have typos, etc.):

• Give an expressive description what you have changed/added and why
• Make sure you're using correct markdown markup
• Make sure all code blocks starts with tripple ``` (backtick) and have a syntax tag, for more read this docs
• Post your addition/changes in issue, we will manage it

Thank you, and do not forget to get rid of this default message