Quieten warning by the code model

QDebug is considered a forward declared type only.

Change-Id: Icd3d544dee04d81bb7087fe6f0153949afad3f10
Reviewed-by: Christian Stenger <christian.stenger@theqtcompany.com>

plugins/autotest/testxmloutputreader.cpp

@@ -23,6 +23,7 @@
 #include <utils/hostosinfo.h>
 #include <utils/qtcassert.h>
 
+#include <QDebug>
 #include <QRegExp>
 #include <QProcess>
 #include <QFileInfo>