pairToPair not working in bedtools > 2.27

pairToPair throw this error only when using a recent bedtools version (it works in 2.27 and below):

```
terminate called after throwing an instance of 'std::invalid_argument'
  what():  stoll
Aborted (core dumped)
```

bedtools was installed in a new conda environment on Linux kernel 5.4.0-166-generic Ubuntu 20.04.2 LTS x86_64.