Re-add APT_TMP_FILE…

Due to a previous unwanted remove…
Otherwise the SGE queue is re-enable in the hour.

cluster/apt.check.update.sh

@@ -176,9 +176,11 @@ main() {                                                        # {{{
 	## }}}
 
 	## If APT package upgrade is available {{{
+	### Create a temp file
 	### Disable SGE queue
 	### AND Exit
 	is_apt_upgrade_present \
+		&& touch "${APT_TMP_FILE}" && echo "APT upgrade is available." >> "${APT_TMP_FILE}" \
 		&& sh "${sge_disable_host_queue_script}" \
 		&& exit 0
 	## }}}