NA/Inf replaced by maximum positive value

When using any functions associated with the Fisher estimator (`fisher.alpha, fisher.rSAC`), I get these warnings:

```Warning messages:
1: In uniroot(function(x) (exp(x) - 1)/x - N/S, c(0.001,  ... :
  NA/Inf replaced by maximum positive value
2: In uniroot(function(x) (exp(x) - 1)/x - N/S, c(0.001,  ... :
  NA/Inf replaced by maximum positive value
...```