Renders an additional non active input field

If editor has no initial input data, then after pressing **enter** in an empty input field there is created an addition not intended input field which does nothing.

### How to reproduce:

1. Delete data object from **new EditorJS** in the example.html
2. In browser, press **tab** twice and then **enter** to create image input field
3. Press **enter** again

Result looks like this:
But pasting image url into the second field does nothing.