do not find the original message when returning batchable messages (#1225)

app/models/queued_message.rb

@@ -111,7 +111,7 @@ class QueuedMessage < ApplicationRecord
       time = Time.now
       locker = Postal.locker_name
       self.class.retriable.where(:batch_key => self.batch_key, :ip_address_id => self.ip_address_id, :locked_by => nil, :locked_at => nil).limit(limit).update_all(:locked_by => locker, :locked_at => time)
-      QueuedMessage.where(:batch_key => self.batch_key, :ip_address_id => self.ip_address_id, :locked_by => locker, :locked_at => time)
+      QueuedMessage.where(:batch_key => self.batch_key, :ip_address_id => self.ip_address_id, :locked_by => locker, :locked_at => time).where.not(id: self.id)
     end
   end