Merge branch '6338-snmpv3' into 'master'

synology: show usage if no param was given

See merge request !76

check_snmp_synology

@@ -195,6 +195,8 @@ _add_status(){
 # MAIN
 # ----------------------------------------------------------------------
 
+test $# -eq 0 && usage
+
 while getopts a:h:f:vsdut OPTNAME; do
     case "$OPTNAME" in
         a)