Code 419 should have been 417 (editorial issue CODES)

When I prepared draft 08, (now rev-00), I goofed and did not properly assign
the response code to be contiguous with previous response codes (416 was
the previous code).

Unless people complain, rev-01 will have the code Expectation Failed
assigned as 417.

			Your editor who couldn't count that high right,
					- Jim