bfast01: error: inadmissable change points: 'from' is larger than 'to'

This call to `Fstat` in `bfast01()` causes an error for some inputs:
https://github.com/GreatEmerald/bfast/blob/6e86571601510ea33af4daa16b0e36564995bd54/R/bfast01.R#L156
The error is `inadmissable change points: 'from' is larger than 'to'`. Setting `trim` to a low number (~7) makes it not give this error any more.

I'd need some input data for reproducing it easier, but overall I'm not sure why that call to `Fstat` is there? In the regular bfast, this functionality is handled by `bfastts` and `bfastpp` instead.