Make core/internal.hpp a private header

modules/flann/src/precomp.hpp

@@ -5,12 +5,8 @@
 #include <cstdarg>
 #include <sstream>
 
-#ifdef HAVE_CVCONFIG_H
-# include "cvconfig.h"
-#endif
 #include "opencv2/core.hpp"
 #include "opencv2/core/utility.hpp"
-#include "opencv2/core/internal.hpp"
 
 #include "opencv2/flann/miniflann.hpp"
 #include "opencv2/flann/dist.h"
@@ -24,5 +20,7 @@
 #include "opencv2/flann/all_indices.h"
 #include "opencv2/flann/flann_base.hpp"
 
+#include "opencv2/core/private.hpp"
+
 #endif