Withdraw older notification before notifying same thing

Author: teamcons

src/Reminder.vala

@@ -68,6 +68,7 @@ public class Badger.Reminder : GLib.Object {
 
     public bool remind () {
         if (global_active && checkbox_active) {
+            app.withdraw_notification (name);
             app.send_notification (name, notification);
         }
         return true;