Allow gamepads even if no mapping is found

[pgivel]

Description

This change was preventing all gamepads to work on Linux. For now we'll allow gamepads even if there is no recognised mapping, and simply log the error. I have no idea how we can detect gamepads for which the mapping is truly broken.

Type of change

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist

• [x] I've read & comply with the contributing guidelines
• [ ] I have tested my code for new features & regressions on both mobile & desktop devices, using the latest version of major browsers.
• [ ] I have made corresponding changes to the documentation (README.md).
• [x] I've checked my modifications for any breaking changes.