N3 - EIP712_DOMAIN_HASH can be calculated at runtime

[PhABC]

By @agusx1211

[Agusx1211]

https://github.com/arcadeum/multi-token-standard/commit/5a4ef26a0be28705086d7eda1fbb3a30cc9ecfec fixes it, but the variable EIP712_DOMAIN_HASH is left unused, maybe it can be removed?

[PhABC]

Good catch