Describe the bug
Setting the following 2 props should result in replacing a single file, however it produces an error every other time. Also not crazy about the end-user experience of showing the files over the maxFile limit with errors on each. It should just replace the files up to the maxFiles size. (I have a workaround for both of these issues in the comment below).
maxFiles={1}
behaviour="replace"

To Reproduce
Steps to reproduce the behavior:

1. Go to https://codesandbox.io/s/dropzone-ui-complete-forked-4wempi
2. Drop a single image multiple times. Every other drop will produce a max files error

Expected behavior
No error should happen for a single file dropped multiple times.

Screenshots
If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari]
• Version [e.g. 22]

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Additional context
Add any other context about the problem here.