improved documentation of retry mode which wasn't clear, while trying to work out if croconaus is supposed to restart maco automatically or not (well it is)

cluster/maco.check.update.sh

@@ -66,7 +66,7 @@ OPTIONS :
         Enable debug messages.
 
     -f,--fail
-        Check update only if the last Maco update failed.
+        enables retry mode: enable this mode to trigger a maco update only if the last Maco update has failed (in this mode a new maco version is not checked).
 
     -h,--help
         Print this help message.
@@ -346,10 +346,10 @@ main() {                                                        # {{{
 		|| exit 0
 	## }}}
 
-	## If MACO_FAILED_MODE wasn't defined (argument, environment variable,…) {{{
-	if [ -z "${MACO_FAILED_MODE}" ]; then
+	## If MACO_RETRY_MODE wasn't defined (argument, environment variable,…) {{{
+	if [ -z "${MACO_RETRY_MODE}" ]; then
 		### Set False by default
-		MACO_FAILED_MODE="1"
+		MACO_RETRY_MODE="1"
 	fi
 	## }}}
 
@@ -384,9 +384,9 @@ Get Maco's versions from webserver."
 	is_var_empty "${CURRENT_MACO_VERSION}" "${LATEST_MACO_VERSION}" "${URGENT_MACO_VERSION}" "${CURRENT_TIMESTAMP}" "${LATEST_TIMESTAMP}" "${URGENT_TIMESTAMP}" \
 		&& exit 1
 
-	## If MACO_FAILED_MODE is set {{{
+	## If MACO_RETRY_MODE is set {{{
 	### Exit if Maco last-update-succeeded
-	if [ "${MACO_FAILED_MODE}" -eq "0" ]; then
+	if [ "${MACO_RETRY_MODE}" -eq "0" ]; then
 		### If Macostatus=last-update-succeeded
 		### Exit
 		is_maco_status_ok \
@@ -432,8 +432,8 @@ if [ ! "${NBARGS}" -eq "0" ]; then
 	while printf -- '%s' "${1}" | grep -q -E -- "^-+"; do
 
 	case "${1}" in
-		-f|--fail )     ## Failed mode
-			MACO_FAILED_MODE="0"
+		-f|--fail )     ## retry mode
+			MACO_RETRY_MODE="0"
 			;;
 		-h|--help )     ## help
 			usage