It's possible to reset primaryCredit and secondaryCredit for insurance account
When because of negative credit after liquidations of another accounts, insurance address doesn't pass `isSafe` check, then malicious user can call JOJOExternal.handleBadDebt and reset both primaryCredit and secondaryCredit for insurance account.\\n`insurance` account is handled by JOJO team. Team is responsible to top up this account in order to cover losses. When bad debt is handled, then its negative credit value is added to the `insurance` account. Because of that it's possible that primaryCredit of `insurance` account is negative and `Liquidation._isSafe(state, insurance) == false`.\\n```\\n    function handleBadDebt(Types.State storage state, address liquidatedTrader)\\n        external\\n    {\\n        if (\\n            state.openPositions[liquidatedTrader].length == 0 &&\\n            !Liquidation._isSafe(state, liquidatedTrader)\\n        ) {\\n            int256 primaryCredit = state.primaryCredit[liquidatedTrader];\\n            uint256 secondaryCredit = state.secondaryCredit[liquidatedTrader];\\n            state.primaryCredit[state.insurance] += primaryCredit;\\n            state.secondaryCredit[state.insurance] += secondaryCredit;\\n            state.primaryCredit[liquidatedTrader] = 0;\\n            state.secondaryCredit[liquidatedTrader] = 0;\\n            emit HandleBadDebt(\\n                liquidatedTrader,\\n                primaryCredit,\\n                secondaryCredit\\n            );\\n        }\\n    }\\n```\\n\\nSo it's possible for anyone to call `handleBadDebt` for `insurance` address, once its primaryCredit is negative and `Liquidation._isSafe(state, insurance) == false`. This will reset both primaryCredit and secondaryCredit variables to 0 and break `insurance` calculations.
Do not allow `handleBadDebt` call with insurance address.
Insurance primaryCredit and secondaryCredit variables are reset.
```\\n    function handleBadDebt(Types.State storage state, address liquidatedTrader)\\n        external\\n    {\\n        if (\\n            state.openPositions[liquidatedTrader].length == 0 &&\\n            !Liquidation._isSafe(state, liquidatedTrader)\\n        ) {\\n            int256 primaryCredit = state.primaryCredit[liquidatedTrader];\\n            uint256 secondaryCredit = state.secondaryCredit[liquidatedTrader];\\n            state.primaryCredit[state.insurance] += primaryCredit;\\n            state.secondaryCredit[state.insurance] += secondaryCredit;\\n            state.primaryCredit[liquidatedTrader] = 0;\\n            state.secondaryCredit[liquidatedTrader] = 0;\\n            emit HandleBadDebt(\\n                liquidatedTrader,\\n                primaryCredit,\\n                secondaryCredit\\n            );\\n        }\\n    }\\n```\\n