message: fix for
  HAVE_QT and HAVE_WIN32UI can both be true at the same time
  if HAVE_QT, window_w32.cpp is not included in the build, see CMakeLists.txt
diff: @@ -93,7 +93,9 @@ CV_IMPL void cvSetWindowProperty(const char* name, int prop_id, double prop_valu
  break;
  case cv::WND_PROP_VSYNC:
  - #if defined (HAVE_WIN32UI)
  + #if defined (HAVE_QT)
  + // nothing
  + #elif defined (HAVE_WIN32UI)
  cvSetPropVsync_W32(name, (prop_value != 0));
  #else
  // not implemented yet for other toolkits
  @@ -191,7 +193,9 @@ CV_IMPL double cvGetWindowProperty(const char* name, int prop_id)
  break;
  case cv::WND_PROP_VSYNC:
  - #if defined (HAVE_WIN32UI)
  + #if defined (HAVE_QT)
  + return -1;
  + #elif defined (HAVE_WIN32UI)
  return cvGetPropVsync_W32(name);
  #else
  return -1;
  