Frailty terms are not supported by function `survreg()`

I think the following sentence is wrong

> in this case you might be able to use `survreg()` and `frailty()` in the survival package for random-intercept models

For details see the last point in the [release note of `survival`](https://cran.r-project.org/web/packages/survival/news.html) version 3.2-9.