fix for memory chart

bin/v-update-sys-rrd-mem

@@ -62,7 +62,11 @@ fi
 if [ "$period" = 'daily' ]; then
     mem=$(free -m)
     used=$(echo "$mem" |grep Mem |awk '{print $3}')
-    free=$(echo "$mem" |grep Mem |awk '{print $4}')
+    if [ -z "$(echo "$mem" | grep available)" ]; then
+        free=$(echo "$mem" |grep buffers/cache |awk '{print $4}')
+    else
+        free=$(echo "$mem" |grep Mem |awk '{print $7}')
+    fi
     swap=$(echo "$mem" |grep Swap |awk '{print $3}')
 
     # Updating rrd