Add metric for HELO_NOT_FQDN

conf/metrics.conf

@@ -702,4 +702,9 @@ metric {
         description = "Message date is in past";
         name = "DATE_IN_PAST";
     }
+    symbol {
+        weight = 1.5;
+        description = "Helo host FQDN check";
+        name = "HELO_NOT_FQDN";
+    }
 }