Qtractor's rubberband transpose eats initial transients

When transposing metro_beat.wav with `rubberband -3 -F -p2 metro_beat.wav metro_beat_rb-processed.wav` then it sounds good. When doing the processing in Qtractor then the initial transients are missing. See attached sample session. [rubberband.qtz.zip](https://github.com/user-attachments/files/21553334/rubberband.qtz.zip)