Error Type getting lost in send_request if error.message is an empty string

[MRigal]

Hi,

For some reason, the "message" attribute seems not to be set or to be an empty strings for httpx TimeoutExceptions.
Thus, using

except httpx.HTTPError as e:
            raise exc_class(str(e)) from e

will also set an empty string and it is not very helpful to distinguish the errors occuring. Replacing by the following already helps.

except httpx.HTTPError as e:
            raise exc_class(str(e) or e.__class__.__name__) from e