Fix token balances after sending out all tokens

[dasanra]

Fixes #1423
Tokens balances aren't updating after sending out all tokens.
There was an issue updating the state for a token that had balance 0

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Type	Occurrences	Fixable
Errors	0	0
Warnings	0	0
Ignored	0	N/A

• Result: ✅ success
• Annotations: 0 total

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^{Report generated by eslint-plus-action}

[ghost]

Travis automatic deployment:
https://pr1521--safereact.review.gnosisdev.com/app

[ghost]

Travis automatic deployment:
https://pr1521--safereact.review.gnosisdev.com/app

[francovenica]

Tested here: https://pr1521--safereact.review.gnosisdev.com/app/#/safes/0x34Ae3245101AC7cF1f805E946C73F33B9286B010/balances

Transfer a few different tokens
Transfer a certain amount of those tokens first. Checked that the tokens would be reduced by that amount
Transfer the whole funds of those tokens. Checked that the token fund are now 0 after those transfers

Looks good to me

[ghost]

Travis automatic deployment:
https://pr1521--safereact.review.gnosisdev.com/app