Define the server listen port as a variable.
Define the server listen port as a variable.

Change-Id: Ia6360c21ca55a283b320588ddf05a77bad7c2515

kernelci/kernelci-backend,joyxu/kernelci-backend,joyxu/kernelci-backend,kernelci/kernelci-backend,joyxu/kernelci-backend