maybe an error in upstakeneedtoPreBoost

From https://github.com/daostack/alchemy/issues/739:

```
I think that if there is an error it is in how ==>this client lib code<== is computing upstakeNeededToPreBoost.

I'd like to figure out how to reproduce the conditions in order to demonstrate whether the bug is still happening.

The client lib test code that might confirm the logic is currently commented out.
```