[5.x] Don't delete asset if replacing itself

[edalzell]

Closes #11229

[jasonvarga]

Thanks for the PR.

With what you've described in #11229, you should be using "reupload" rather than "replace".

You might run into caching issues when uploading an identically named file, and the "reupload" action already tries to handle those as best as it can.

I think we'd be better off updating the validation within the modal for your situation. Or maybe prevent the overwrite option within the "Fix.." dropdown there.