Add failed embed for /listremind (#88)

Without this embed, if there are no reminders created by the user, the
bot will endlessly think because StringBuilder will be empty and normal
embed will not be shown.

src/Messages.Designer.cs

@@ -995,5 +995,11 @@ namespace Boyfriend {
                 return ResourceManager.GetString("ReminderDeleted", resourceCulture);
             }
         }
+
+        internal static string NoRemindersFound {
+            get {
+                return ResourceManager.GetString("NoRemindersFound", resourceCulture);
+            }
+        }
     }
 }