Redundant check in `SherBuy.execute`

[code423n4]

Handle

ych18

Vulnerability details

SherBuy.execute uses the function viewCapitalRequirements which checks whether the liquidity event is active with if (active() == false) revert InvalidState();. Then SherBuy.execute uses SherClaim.add which also checks for the same thing with the active function in L62:

• the active() function is SherClaim checks if block.timestamp >= claimableAt;
• the active() function is SherBuy checks if block.timestamp < SherClaim.claimableAt;