Fix typo "Model" is correct spelling not "Modle"

Fix typo "Model" is correct spelling not "Modle"

Maybe be squashed into :

5f505cf352f0f5fd675b3f97662b5f243dd2f89e
https://gerrit.iotivity.org/gerrit/#/c/8325/

Bug: https://jira.iotivity.org/browse/IOT-1100
Change-Id: If13b0155b1d94ce2bb362ed4cf580b2879e84090
Signed-off-by: Philippe Coval <philippe.coval@osg.samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/8639
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: David Antler <david.a.antler@intel.com>
Reviewed-by: Ziran Sun <ziran.sun@samsung.com>