query.fetch raises unhandled error when it finishes to retry

[amitripshtos]

Hey,
When you are using "useQuery" with the parameters:

{ refetchInterval: 1000 }

And the function which fetches the data raises error multiple time (and retrying is being finished), an exception will be thrown without any handling.

How to test it:

1. Open the Codesandbox of react-query
2. in line 62 change errorRate to be 1
3. In line 357 add the refetchInterval property

 } = useQuery(["todos", { filter }], fetchTodos, { refetchInterval: 1000 });

4. After few seconds the UI will show the unhandled exception

How to fix that:
Basically I think that in query.fetch the in line 366 at "index.js" the "throw error" is causing the issue. I'm not sure why we need to throw that error there so I would like a second eye for that.

Thanks,
Amit.

[barrymay]

@tannerlinsley please check out my PR when you can, I believe it fixes the problem as desired.