Error extracting audio from a video with multiple audio tracks

**Describe the bug**
Extract mp3 from video broke when the file has more than 1 audio track

**To Reproduce**
Steps to reproduce the behavior:
add a video 
select convert to mp3

**Expected behavior**
No error, extract a default track, or allow to select one track


**Desktop (please complete the following information):**
 - OS: PoP oS
