title: Qt can not slot by name, even after objectName was set
body: <p>It occurs when I try to use the Qt auto signal to slot connection using Qt meta object's ability. I try to create a QTimer object, and changed its name, but slot could not match the signal, I don't know why. Here's my code:</p>
  
  <p>mytimer.h:</p>
  
  <pre><code>#ifndef MYTIMER_H
  #define MYTIMER_H
  
  #include &lt;QMainWindow&gt;
  #include &lt;QTimer&gt;
  
  namespace Ui {
  class MyTimer;
  }
  
  class MyTimer : public QMainWindow
  {
      Q_OBJECT
  
  public:
      explicit MyTimer(QWidget *parent = 0);
      ~MyTimer();
  
  private:
      Ui::MyTimer *ui;
      QTimer *timer;
  private slots:
      void on_timerOne_timeout();
  };
  
  #endif // MYTIMER_H
  </code></pre>
  
  <p>mytimer.cpp:</p>
  
  <pre><code>#include "mytimer.h"
  #include "ui_mytimer.h"
  #include &lt;QTimer&gt;
  #include &lt;QDebug&gt;
  
  MyTimer::MyTimer(QWidget *parent) :
      QMainWindow(parent),
      ui(new Ui::MyTimer)
  {
      ui-&gt;setupUi(this);
      timer = new QTimer(this);
      timer-&gt;setObjectName("timerOne");
      // connect(timer, &amp;QTimer::timeout, this, &amp;MyTimer::MySlot);
      timer-&gt;start(1000);
  }
  
  MyTimer::~MyTimer()
  {
      delete ui;
  }
  
  void MyTimer::on_timerOne_timeout()
  {
      qDebug() &lt;&lt; "Timer running...";
  }
  </code></pre>
  
  <p>After I changed timer's ObjectName to timerOne, signal-slot-auto-connection : </p>
  
  <pre><code>void MyTimer::on_timerOne_timeout() 
  </code></pre>
  
  <p>could not run correctly. </p>
  
  <p>using Qt 5.5.0</p>