Delete client callback with OCCancel.
Delete client callback with OCCancel.

Change-Id: I3bde95b535fcbfd3290a7b9ae0610c3e9333be7a
Signed-off-by: Jaehong Jo <69db334b3f87f30654728856fde276b43c835fe5@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/20299
Tested-by: jenkins-iotivity <d95b56ce41a2e1ac4cecdd398defd7414407cc08@iotivity.org>
Reviewed-by: Dan Mihai <ba8e1833495515b49ded9e20cae80a8129155aa9@microsoft.com>
(cherry picked from commit 94429e77972ccabbbaed53a850d4de27fa56de9c)

rzr/iotivity,iotivity/iotivity,iotivity/iotivity,rzr/iotivity,rzr/iotivity,iotivity/iotivity,rzr/iotivity,iotivity/iotivity,rzr/iotivity,iotivity/iotivity,rzr/iotivity,rzr/iotivity,iotivity/iotivity,iotivity/iotivity,iotivity/iotivity