Modify a typing error of help message.

Modify a typing error of help message.

A name of this file is OICMiddle, but there is a typing error
in help message. So modify from IOCMiddle to OICMiddle.

Change-Id: I29be198ca313022753531088e53d5d47c61fef36
Signed-off-by: Jake Kim <copy_x@naver.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/1405
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Phil Coval <philippe.coval@osg.samsung.com>
(cherry picked from commit 2210aba65dbecdf56a2ff5377bf3b76234803342)
Reviewed-on: https://gerrit.iotivity.org/gerrit/14569