title: updateMyvCardTemp in xmppframework
body: <p>i try to update myvcard,but always receive a error message ,</p>
  
  <p>《error code="400" type="modify"》  《bad-request xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"/》《/error》</p>
  
  <p>my code :</p>
  
  <pre><code>XMPPvCardTemp *mycard=[self.appdel.xmppHelper getmyvcard];
  NSLog(@"nickname:%@",mycard.nickname);
  NSLog(@"name:%@",mycard.name);
  NSLog(@"location:%@",mycard.location);
  NSLog(@"jid:%@",mycard.jid);
  NSLog(@"title:%@",mycard.title);
  mycard.title=@"lkasjdfl";
  mycard.nickname=@"jdjdjdjd";
  mycard.jid=[XMPPJID jidWithString:@"test@im.xujialiang.net"];
  [self.appdel.xmppHelper updateVCard:mycard];
  </code></pre>