fix con_replic query

Author: terrywbrady

app/config/mrt/query.sql.yml

@@ -2295,6 +2295,8 @@ queries:
                 then 0
               when u.modified < date_add(now(), INTERVAL -1 DAY)
                 then 0
+              when u.modified is null
+                then 0
               else 1
             end
           ),