Double indexes with collection in a table

[FBL-dev]

Hello,

I notices a bug. If you go to your demo page:
https://symfony-collection.fuz.org/symfony3/basic/inATable

Delete the last two fields (Mininal bought quantity : 26 and 11).

Inspect the first field, you will see it has ID 'DiscountCollectionType_discounts_0_quantityFrom'

Now, do the following:

- Add element from the first field or duplicate the first field

You will notice, the new field have ID 'DiscountCollectionType_discounts_3_quantityFrom'.

[FBL-dev]

Anyone have a temporary solution to suggest doing to resolve this problem? Thank you