In CentOS, the path of "ExecStart" in tacker.service file is different from "/usr/local/bin/tacker-server", so it is unable to start Tacker successfully. In order to avoid this issue, fixed the code so that it is available for multiple distributions. Change-Id: I2e559523f6bcf57bffd693a4631f72ac339ac4eb Closes-Bug: #1874384