Problem regarding NON request on Slow Response server

Problem regarding NON request on Slow Response server

When a slow responding server receives a NON type request,
it is sending back an ACK message immediately, and then later,
sending NON response. According to RFC-7252, response of NON request
should only be a NON, there should not be any ACK in between.

Change-Id: I0b00c2423660d622df8490bf03011d18a1c26126
Signed-off-by: hyuna0213.jo <hyuna0213.jo@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/7385
Reviewed-by: jihwan seo <jihwan.seo@samsung.com>
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Ashok Babu Channa <ashok.channa@samsung.com>