Check if Synapse-Admin service exists (#4050)

ct/elementsynapse.sh

@@ -47,6 +47,7 @@ function update_script() {
   $STD apt-get -y upgrade
   msg_ok "Updated $APP LXC"
 
+  if [[ -f /systemd/system/synapse-admin.service ]]; then
     msg_info "Updating Synapse-Admin"
     RELEASE=$(curl -fsSL https://api.github.com/repos/etkecc/synapse-admin/releases/latest | grep "tag_name" | awk '{print substr($2, 3, length($2)-4) }')
     if [[ "${RELEASE}" != "$(cat /opt/"${APP}"_version.txt)" ]] || [[ ! -f /opt/${APP}_version.txt ]]; then
@@ -65,6 +66,7 @@ function update_script() {
     else
       msg_ok "No update required. ${APP} is already at v${RELEASE}"
     fi
+  fi
   exit
 }