QtTest: qDebug output counted as <system-err> (std error output) in junitxml

QDebug output in a test is counted as an error in junitxml.

Steps to reproduce the issue:

• Run the attached test with -o output.xml,junitxml
• Check the .xml file

  <?xml version="1.0" encoding="UTF-8" ?>
  <testsuite name="Test" timestamp="2021&#x002D;01&#x002D;12T12:33:07+01:00" tests="3" failures="0" errors="1" time="0.005474">
    <properties>
      <property name="QTestVersion" value="6.1.0"/>
      <property name="QtVersion" value="6.1.0"/>
      <property name="QtBuild" value="Qt 6.1.0 (x86_64&#x002D;little_endian&#x002D;llp64 shared (dynamic) debug build; by MSVC 2019)"/>
    </properties>
    <testcase name="initTestCase" result="pass" time="0.001225"/>
    <testcase name="test_case1" result="pass" time="0.003018">
      <!-- type="qdebug" message="I appear as an error in junitxml" -->
    </testcase>
    <testcase name="cleanupTestCase" result="pass" time="0.000004"/>
    <system-err>
  <![CDATA[I appear as an error in junitxml]]>
    </system-err>
  </testsuite>
  

See https://llg.cubic.org/docs/junit/