Fix Guzzle error processing with http_errors=true

[savchukoleksii]

When Guzzle option http_errors=true this errorResponses not processing and this code skipped during exception: yield $this->transformResponseToResult($response, $request, $command); This fix allow errorResponses mappings from Description. If error not found in errorResponses than Guzzle error will propagate.

[savchukoleksii]

@GrahamCampbell Done

[GrahamCampbell]

Could you add a unit test please? Then I'll be happy to merge.

[savchukoleksii]

@GrahamCampbell sorry, have not time for continue this pr. Can you help me with tests?

[GrahamCampbell]

I don't have any capacity for this. I think we just need to say that that we require people not use that mode.