Are you submitting a bug report or a feature request?

Bug report

What is the current behavior?

• Select topic 3 or 4 to show the input (message field will be registered for the first time)
• Type something into the input
• Select topic 1 or 2 (message field is unregistered)
• Again select topic 3 or 4. At this point dirty flag is set to true
• Once again type something into the input and then clear the value. Now you should see correct dirty value which is false

What is the expected behavior?

Message field should not be marked as dirty when is registered for the second time. This happens only when destroyOnUnregister option is enabled.

Sandbox Link

https://codesandbox.io/s/nn91pmm96p

What's your environment?

Final-form 4.10.0