title: Strophe MAM does not return messages after first run
body: <p>I have written a function to get archived messages between two dates from ejabberd server. It returns messages when it first run but does not return any message after first run.
  Here is my code:</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>function getMessageHisttory(jid) {
      var end = otherUser.oldestMessageDate;
  
      var start = new Date();
      start.setDate(end.getDate() - 2);
      STROP.connection.mam.query($scope.selfIdUser, {
          "with": $scope.otherIdUser,
          "start": start.myFormat(),
          "end": end.myFormat(),
          onMessage: function (message) {
              console.log('Message: ', message);
              return true;
          },
          onComplete: function (response) {
              otherUser.oldestMessageDate = start;
              console.log("Completed");
          }
      });
  }</code></pre>
  </div>
  </div>
  </p>
  
  <p>Any idea about what I am doing wrong?</p>