setPositionRouter leaks approval to previous positionRouter
positionRouter is used to change GMX positions in GMXFuturesPoolHedger. It can be replaced by a new router if GMX redeploys, for example if a bug is found or the previous one is hacked. The new positionRouter receives approval from the contract. However, approval to the previous positionRouter is not revoked.\\n```\\n    function setPositionRouter(IPositionRouter _positionRouter) external onlyOwner {\\n      positionRouter = _positionRouter;\\n        router.approvePlugin(address(positionRouter));\\n    emit PositionRouterSet(_positionRouter);\\n       }\\n```\\n\\nA number of unlikely, yet dire scenarios could occur.
Use router.denyPlugin() to remove privileges from the previous positionRouter.
```\\n    function setPositionRouter(IPositionRouter _positionRouter) external onlyOwner {\\n      positionRouter = _positionRouter;\\n        router.approvePlugin(address(positionRouter));\\n    emit PositionRouterSet(_positionRouter);\\n       }\\n```\\n