[production] render_exception does not correctly render exceptions

[regineheberlein]

Expected behavior

The error should contain a meaningful backtrace

Actual behavior

The error contains unknown instead of actual data

Steps to replicate

this proved trickier than we thought, TBD!

Impact of this bug

This makes it hard to troubleshoot

Acceptance criteria

• an error is raised when, as appears to be the case here, the server is being accessed unauthorized
• the error contains meaningful data in the backtrace

Honeybadger link and code snippet, if applicable

https://app.honeybadger.io/projects/102902/faults/116353268

ArgumentError: wrong number of arguments (given 3, expected 2)
unknown  ?  unknown(...)
unknown:?:in `unknown'

Implementation notes, if any

Relates to https://app.honeybadger.io/projects/102902/faults/115720788