remove various 18.04 specific code

src/scripts/restartservice.sh

@@ -34,15 +34,8 @@ elif [[ "${service}" == "docker" ]]; then
 elif [[ "${service}" == "collectd" ]]; then
     systemctl restart --no-block collectd
 elif [[ "${service}" == "box" ]]; then
-    readonly ubuntu_version=$(lsb_release -rs)
-    if [[ "${ubuntu_version}" == "18.04" ]]; then
-        pid=$(systemctl show box -p MainPID | sed 's/MainPID=//g')
-        kill -HUP $pid
-    else
-        systemctl reload --no-block box
-    fi
+    systemctl reload --no-block box
 else
     echo "Unknown service ${service}"
     exit 1
 fi
-