Submitted by gpersoon
In PrizePool.sol, if the value of  _tokenCreditPlans[_controlledToken].creditRateMantissa isnt set (yet), then the function _estimateCreditAccrualTime returns 0.
This means the TimelockDuration is 0 and funds can be withdrawn immediately, defeating the entire timelock mechanism.
Recommend perhaps a different default would be useful.
PrizePool.sol L783
PrizePool.sol L710
Recommend considering the default duration for the case _tokenCreditPlans[_controlledToken].creditRateMantissa isnt set.
