Fix mbedtls-2.4.0 build error

Fix mbedtls-2.4.0 build error

.git/refs/tags directory is empty

Change-Id: I0127bd3c8cb5448a8b7081b5f9550c6e502db7f0
Signed-off-by: Dmitriy Zhuravlev <d.zhuravlev@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/14223
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Kevin Kane <kkane@microsoft.com>
Reviewed-by: Dan Mihai <Daniel.Mihai@microsoft.com>
Reviewed-by: Chul Lee <chuls.lee@samsung.com>
Reviewed-by: Phil Coval <philippe.coval@osg.samsung.com>
Reviewed-by: Uze Choi <uzchoi@samsung.com>