Lack of a check for the subject's stake for reviewSlashProposalParameters
In the `SlashingController` contract, the address with the `SLASHING_ARBITER_ROLE` may call the `reviewSlashProposalParameters()` function to adjust the slashing proposal to a new `_subjectId` and `_subjectType`. However, unlike in the `proposeSlash()` function, there is no check for that subject having any stake at all.\\nWhile it may be assumed that the review function will be called by a privileged and knowledgeable actor, this additional check may avoid accidental mistakes.\\n```\\nif (subjectGateway.totalStakeFor(\\_subjectType, \\_subjectId) == 0) revert ZeroAmount("subject stake");\\n```\\n\\n```\\nif (\\_subjectType != proposals[\\_proposalId].subjectType || \\_subjectId != proposals[\\_proposalId].subjectId) {\\n    \\_unfreeze(\\_proposalId);\\n    \\_freeze(\\_subjectType, \\_subjectId);\\n}\\n```\\n
Add a check for the new subject having stake to slash.
```\\nif (subjectGateway.totalStakeFor(\\_subjectType, \\_subjectId) == 0) revert ZeroAmount("subject stake");\\n```\\n