Fix deadlock when browser process does not launch

HelperProcess::toForeground()

{

#if defined(Q_WS_MAC)

  if(state() != QProcess::Running)

    return;

  ProcessSerialNumber psn;

  OSStatus st;

  do {

    st = GetProcessForPID(pid(), &psn);

  } while(st == -600);

    QCoreApplication::processEvents();

  } while(st == procNotFound and state() == QProcess::Running);

  if(st != procNotFound)

    SetFrontProcess(&psn);

#endif

}