#3591689: Too many redirects in invalid langcode as path-prefix
[Description of changes]
Testing instructions
- Add additional language at
admin/config/regional/language/add - Change path prefix to something random (frtest) at
/admin/config/regional/language/detection/url - Visit /frtest/canvas to observe to get error ERR_TOO_MANY_REDIRECTS
- Switch to this MR to see that now the issue is fixed.
Closes #3591689