Conversion window limit cannot delete

[darkopia]

Bug Description

Bug description

Please describe.

It can be a little tricky to amend the Conversion window limit in a funnel because its set to a number with a minimum value I think the validation does not let you remove the value entirely to replace it you have to highlight and change or use the arrows up and down

How to reproduce

1. Create a funnel
   2.Attempt to amend the Conversion window limit by deleting the number to change it
2. You cannot delete the number

Additional context

Debug info