Fixed line endings in the gradlew script

Fixed line endings in the gradlew script

The gradlew script must have linux style line endings.
This is need to avoid a 'No such file or directory'
error.

Change-Id: Idcd2b46fb61e5e2b938f46963eb2f298c8a3436d
Signed-off-by: George Nash <george.nash@intel.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/10237
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Tim Kourt <tim.a.kourt@intel.com>
Reviewed-by: Larry Sachs <larry.j.sachs@intel.com>
Reviewed-by: Ashok Babu Channa <ashok.channa@samsung.com>