Make the message in JSON error responses translatable#386

When debug mode is off, the message that is included with JSON error responses is a hard-coded message in English. Would it be possible to make that string translatable?

As well as supporting other languages, you could then potentially override that message to display something a little more appropriate for non-developers (e.g. “An unexpected error occurred. An administrator has been notified.”).

Happy to make a pull-request for this admittedly incredibly minor suggestion!

@Damien Dart A pull request for this is very welcome. Please add a link to your suggestion in the PR description so we can reference it later.