fix(install): remove redundant assignment of service_config in instal…

…l_service_on_systemd function

packaging/tools/install.sh

@@ -1047,7 +1047,6 @@ function clean_service_on_systemd() {
 function install_service_on_systemd() {
   clean_service_on_systemd $1
   service_config="${service_config_dir}/$1.service"
-  service_config="${service_config_dir}/$1.service"
   cfg_source_dir=${script_dir}/cfg
   if [[ "$1" == "${xname}" || "$1" == "${explorerName}" ]]; then
     if [ "$verMode" == "cluster" ] && [ "${entMode}" != "lite" ]; then