s3.TUP Follow renaming freetz-revision like freetz-ng

and ensure working with older freetz-ng revisions without that new naming
see: 989df7ee59 (diff-12343fb98b8317fa6556b88485bbf742e6aed3d48d28858e70b0f924ac5e290a)

support/functions/_plugin_update_toolchain

@@ -462,7 +462,7 @@ _create_tc(){
 											buildtasks+=("$task");
 										done;;
 								"FNG")  
-										echo -e "${g_l}\n$(tools/freetz-revision 2>&1 | tail -1)\n${re_}" | _log "$logfile";
+										echo -e "${g_l}\n$([ -f "tools/freetz-revision" ] && tools/freetz-revision || tools/freetz_revision 2>&1 | tail -1)\n${re_}" | _log "$logfile";
 										[[ ! $(umask) == 0022 ]] && umask 0022;
 										for task in "${FNG_BUILD_tasks[@]}";do
 											task=$(_replace_tokens "$task");	#replace tokens