PHP warnings/errors in WordPress API crash frontend

[simonrjones]

Issue
The API was trying to json_decode() an API response, but the response had a couple of PHP warning messages at the start due to the backend having some missing media items. This caused json_decode() to fail and throw up a JSON syntax error exception (FailedRequestException). This returned an error 500.

What I'd expect
Not sure, a production site would return a Server Error 500 page which is correct. Do we want to supress these errors and ensure we can return content to a user?

/cc @sean-dunwoody @gtrinkwon

[simonrjones]

Should no longer be an issue since can now supress HTTP errrors for sub-requests