[JIRA-1151] IoTivity Blockwise transfer is sort of broken when

[JIRA-1151] IoTivity Blockwise transfer is sort of broken when
paired with slow response

- When a resource is set as slow response resource,
and it has a large enough payload to be sent as blockwise
transfer data, and a CON retrieve message is sent to the resource,
the coap messaging mechanism break down.
- Remove the unnecessary code

Change-Id: I4bfabc4f457f637a8a88e6c237c25831c7b6c776
Signed-off-by: hyuna0213.jo <hyuna0213.jo@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/8895
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Mushfiqul Islam <i.mushfiq@samsung.com>
Reviewed-by: jihwan seo <jihwan.seo@samsung.com>
Reviewed-by: Ashok Babu Channa <ashok.channa@samsung.com>