message: videoio(msmf): fix build warning
  warning C4800: 'int': forcing value to bool 'true' or 'false'
diff: @@ -1797,7 +1797,7 @@ CvResult CV_API_CALL cv_writer_open(const char* filename, int fourcc, double fps
  {
  wrt = new WriterT();
  Size sz(width, height);
  - if (wrt && wrt->open(filename, fourcc, fps, sz, isColor))
  + if (wrt && wrt->open(filename, fourcc, fps, sz, isColor != 0))
  {
  *handle = (CvPluginWriter)wrt;
  return CV_ERROR_OK;
  