garbled code in job setting - when create and set

[iTryIt]

Sending configures in xml. I keep xml file in UTF8 encoding as usual. But seems that Jenkins refuse to decode xml in UTF8 without the header charset below.

public function createJob($jobname, $xmlConfiguration)
{
  /*
    ******
  */

  $headers = array('Content-Type: text/xml;charset=utf-8'); //Add encoding charset to header

  /*
    ******
  */
}

public function setJobConfig($jobname, $configuration)
{
  /*
    ******
  */

  $headers = array('Content-Type: text/xml;charset=utf-8'); //Add encoding charset to header

  /*
    ******
  */
}