Fix exception objects not being logged properly

[Sharparam]

Description

The order of arguments sent to _logger.Error in ExceptionHandlingMiddleware was incorrect, causing exception objects to not be logged properly. The exception object was passed in as a format parameter, but as the log message didn't contain any formatting placeholders, the exception object was lost in the resulting log output.

This change puts the exception object as the first argument, as the Error log method requires.

This fixes #340.

Check List

• [?] All test passed. There are tests that are failing in the current 2.0 so I'm not sure what to make of that.
• [X] Added documentation (if applicable).
• [ ] Tests added to ensure functionality. Not sure how to test for log output correctness?
• [ ] Pull Request to stable branch. N/A, this change is for 2.0.

[pardahlman]

Nice catch, thanks a lot 👌

[Sharparam]

@pardahlman Any plans on a new release candidate to include this and possibly other fixes? It's getting increasingly difficult to debug issues with RawRabbit as it does not log the exceptions thrown in the current rc-5 release.