Since late last week, the following error appears regularly:
```
$ gpac -i avgen:dur=4 reframer -o null
[avgen] Error initializing filter
[avgen] Error: Font SANS not found and no default font available!
Check your GPAC configuration, or use `-rescan-fonts` to refresh font directory.

    at put_image (/home/rbouqueau/works/gpac/gpac/share/scripts/jsf/avgen/init.js:355)
    at <anonymous> (/home/rbouqueau/works/gpac/gpac/share/scripts/jsf/avgen/init.js:245)

Error Bad Parameter while instantiating filter jsf
Failed to load filter for "avgen:dur=4": Bad Parameter

```

```gpac -rescan-fonts``` doesn't work but ```rm -rf ~/.gpac``` does. However the errors comes back again regularly.

I am on Debian. @nlsdvl also had the issue on Ubuntu.
Font scan issue
This is a GitHub Issue
repo:gpac
owner:gpac
Title : Font scan issue
Issue date:

--- start body ---
Since late last week, the following error appears regularly:
```
$ gpac -i avgen:dur=4 reframer -o null
[avgen] Error initializing filter
[avgen] Error: Font SANS not found and no default font available!
Check your GPAC configuration, or use `-rescan-fonts` to refresh font directory.

    at put_image (/home/rbouqueau/works/gpac/gpac/share/scripts/jsf/avgen/init.js:355)
    at <anonymous> (/home/rbouqueau/works/gpac/gpac/share/scripts/jsf/avgen/init.js:245)

Error Bad Parameter while instantiating filter jsf
Failed to load filter for "avgen:dur=4": Bad Parameter

```

```gpac -rescan-fonts``` doesn't work but ```rm -rf ~/.gpac``` does. However the errors comes back again regularly.

I am on Debian. @nlsdvl also had the issue on Ubuntu.
--- end body ---
