Currently, we always set the content-format as "plain/text" when
it is unrecognized. This is wrong for it's possible that payload
is actually something else.
For example, we don't support JSON as incoming format right now.
But if I send a PUT request to /1/0/1 (server objectinstance/lifetime
resource) with value 3200 in JSON format: {"e":[{"n":"","v":3200}]}.
The client will still handle the request and respond with changed (2.04)
except the lifetime resource is updated incorrectly due to parsing
error.
Correct the behavior by not setting a default format and respond with
content-format-not-support error code (4.15)
Signed-off-by: Robert Chou <robert.ch.chou@acer.com>
54d7207e09