The constructor of IncentiveDistribution take as argument the address of MFI token but it doesnt check that is != address(0). Not worth an issue alone but IncentiveDistribution imports IERC20.sol and never uses it.
In case the address(0) is passed as argument the withdrawReward would fail and due to the fact that MFI is immutable the only solution would be to redeploy the contract meanwhile losing trust from the users.
Deploy IncentiveDistribution with 0 as \_MFI argument and then call withdrawReward.
