When a response fails to be completely emitted by the remote (connection
termination during the transmission of the response for example), a
WebClientResponseException can be propagated with a confusing message
which mainly reflects the status code and reason phrase, leading to
messages like "200 OK" in such an exception.
This change improves the situation by appending a hint at the underlying
cause whenever getMessage() is called on a WebClientResponseException
which was created with a non-error status code.
Closes gh-33127
06d267f04e