bug: episode duration does not work properly in french
### Describe the bug
episode duration does not work properly in french
### Steps to reproduce
1. Configure your browser in french
2. go to an episode page (admin or public)
3. take a look at the episode duration
### Expected behavior
Display duration in mn/sec
### Actual behavior
Displays duration in sec only
### Relevant logs and/or screenshots

https://podcast.podlibre.org/@fr/le-marche-du-podcast
### Context
- Castopod: pipeline 183
- OS: Debian 10.5
- Browser: Firefox
- Web server: NGinx
- Cloud Panel
### Possible fixes
Update the french format
issue