Steps to reproduce

1. Go to Demo and open the Assets app
2. Click on upload new asset and within the detail view, select the test.js file
3. Upload it and check no security check is performed (asset uploaded)
4. Now try the "Upload zip archive" with the test.js.zip file
5. Check the security check prevents the user to upload the file

Expected results

Validator should detect correct mimeType for file. Javascript file could be uploaded if zipped or not. 

Actual results

If not zipped, the file is uploaded

Workaround

N/A

Development notes

N/A