title: Local notification "schedule" and "trigger" methods are executing multiple times
body: <p>Hi I'm new on ionic and I'm using (katzer/cordova-plugin-local-notifications), I have a problem and I don't know what is happening.</p>
  
  <p>When I click in a link, I'm generating a new notification. But I don't know for what when I click for the second time in the notification, the alert inside of "schedule" and "trigger" is executed two times, and when I click for the third time in the notification, the alert inside of "schedule" and "trigger" is executed three times, and so..</p>
  
  <p>This is my code, it's very simple:</p>
  
  <pre><code>$scope.addNotification = function (){
  
  
      var idaudio = Math.round(Math.random() * 10000);
      var date = Date.now();
  
      cordova.plugins.notification.local.schedule({
          id: idaudio,
          title: 'Remember',
          text: 'New Remember',
          at: date
  
      });
  
  
      cordova.plugins.notification.local.on("schedule", function(notification){
          alert("scheduled: " + notification.id);
      });
  
  
      cordova.plugins.notification.local.on('trigger', function (notification){
          alert("trigger" + notification.id)
      });
  }
  </code></pre>
  
  <p>I need that when I click in a notification only one alert print the related notification id. </p>
  
  <p>Can anyone help me please?</p>
  
  <p>Thanks in advance.</p>