fixed create response in message builder

fixed create response in message builder

when create response message, it is unnecessary to set observe option.

Change-Id: I293843dac9bdbcc3d1b88724d15c89f229649fde
Signed-off-by: Jung Seungho <shonest.jung@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/11661
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Jee Hyeok Kim <jihyeok13.kim@samsung.com>
(cherry picked from commit fef945f09258318fc799210618c7115648df51b3)
Reviewed-on: https://gerrit.iotivity.org/gerrit/11959