Need logic to handle first User and last User

[0xVonBismarck]

https://github.com/CanzaApps/Baki-contracts/blob/a30a237c6468ffd4b45eca6f125c6f487b305cce/contracts/Vault.sol#L573

As discussed, we need logic to handle the first user and the last user in the platform when the NetMint would be 0. Therefore in that case we should return true for this function.